Background

“The zone appearing most distant within a pictorial composition, perceived as lying farthest from the viewer in the depicted spatial hierarchy. It often contains elements that are rendered with lower contrast, reduced detail, softened edges, and muted or cooler color temperatures—all of which serve as depth cues that support aerial perspective and the perception of spatial recession.

Functionally, the background provides contextual and environmental support for foreground and midground elements. It can: establish atmospheric or narrative setting, reinforce depth through spatial cues (e.g., overlapping, size diminution, desaturation), and act as a compositional foil that amplifies the salience of primary subjects.

From a perceptual standpoint, background differentiation is informed by several monocular depth cues, including blur gradients, chromatic dulling, and luminance convergence, which simulate the visual effects of distance in natural viewing conditions. The background may also exhibit lower spatial frequency content, a characteristic associated with how the visual system processes distant information.

Historically, background treatment has been a critical compositional tool. In linear perspective systems developed during the Renaissance, backgrounds recede toward a vanishing point to structure the illusion of depth. In atmospheric or tonal painting, particularly in landscape traditions, backgrounds are lightened and desaturated to mimic atmospheric diffusion. In contrast, modernist and abstract traditions often flatten or eliminate background treatment altogether, challenging the spatial hierarchies of earlier pictorial conventions.

Although often passive in narrative function, the background plays an essential role in structuring visual hierarchy, anchoring spatial relationships, and managing viewer navigation across the pictorial field.”

Backscatter

“The reflection or scattering of light back toward the viewer after it interacts with small particles in the atmosphere or a diffuse surface. One useful way to think about it is to think of light as a collection of tiny particles thrown into a misty field—some bounce back toward you after hitting fog droplets, creating a veil of brightness that doesn’t come directly from the object, but from the space between you and it. This phenomenon contributes to the lightening, desaturation, and softening of distant objects, and is a key optical mechanism behind aerial (atmospheric) perspective.

Backscatter is one of the major contributors to ambient light—the diffuse, omnidirectional illumination present in an environment. While ambient light can originate from multiple reflections off nearby surfaces or particles, backscatter is the specific subset that involves light being redirected toward the viewer from particulate interaction. This scattered light reduces the contrast and saturation of distant forms and overlays them with a bluish or whitish haze, particularly under humid, dusty, or smoky conditions.

Unlike directional reflection (e.g., highlights), backscattered light is diffuse and angle-independent, caused by the scattering of short wavelengths (associated with blue) from particles such as fog, dust, or vapor. In representational art, simulating backscatter involves the strategic reduction of contrast, compression of values, and lowering of chroma in receding space—not simply blurring or fading detail, but mimicking the specific visual interference caused by ambient particulate diffusion.

Understanding backscatter allows artists to more accurately render depth, spatial atmosphere, and environmental realism through empirical manipulation of pictorial variables rather than symbolic or generalized fading.”

Balance

“The perceptual experience of equilibrium or stability in a visual composition, achieved through the intentional distribution of visual weight across a pictorial field. In this context, visual weight is a perceptual construct determined by factors such as size, contrast, position, color, shape, texture, and informational density. When these elements are arranged in a manner that avoids dominance or dissonance across regions of the image, the result is often perceived as balanced.

Pictorial balance is not defined by strict symmetry alone. There are multiple types of balance:

Symmetrical balance involves even distribution relative to a central axis, often evoking formality and stasis.

Asymmetrical balance achieves equilibrium through contrasting elements of different visual weight arranged in a dynamic but stable configuration.

Radial balance organizes elements around a central point.

Ambiguous or neutral balance describes equilibrium in compositions where relationships are unclear or seem to appear colloquially random, but still result in perceptual stability​.

Balance perception is strongly influenced by biological and neurological factors. For instance, vertical mirror symmetry is processed more fluently by the visual system and is often perceived as more balanced than horizontal or diagonal symmetry. Similarly, viewers tend to interpret the upper half of a frame as ‘heavier’ than the lower half, consistent with natural scene statistics and ecological priors​.

While traditional art theory often equates balance with harmony or beauty, the Waichulis Curriculum emphasizes that intentional imbalance can be just as effective—used to evoke tension, movement, or unease. Thus, balance is understood not as a rule to be followed, but as a tool for perceptual control, enabling the artist to align compositional structure with communicative goals.”

Banding (Gradients)

“A visual artifact in digital or physical gradations where smooth transitions between values or colors break into visible, discrete steps or ‘bands.’ In digital media, banding typically results from insufficient bit depth, which limits the number of tonal steps that can be displayed between two values. In physical media (e.g., drawing or painting), banding often emerges from inconsistent application pressure, poor load modulation, or incorrect tapering—producing abrupt changes that disrupt perceptual continuity.

From a perceptual standpoint, banding can often be understood as a rate issue within a gradation’s structure. According to the Waichulis Curriculum, all gradations can be analyzed by two interdependent attributes: range (the difference between the endpoints of a transition) and rate (how quickly that change occurs across space). When the rate of change is not modulated smoothly—such as an overly fast shift over a short distance without proper tapering—it can result in banded transitions that appear artificial or structurally inconsistent​.

In this context, avoiding banding requires not just matching values at endpoints, but controlling the rate of change with enough resolution—through careful pressure control, stroke modulation, or blending technique—to produce a perceptually continuous transition. Training exercises such as the Gradation Block and Gradation Pattern in the Waichulis Curriculum explicitly target this sensitivity and control, helping learners to diagnose and correct banding through tactile and visual calibration​.”

Baroque

“The dominant visual style in European art from the late 16th to the early 18th century, characterized by dramatic contrasts, dynamic movement, theatrical composition, and heightened emotional content. Baroque artists such as Caravaggio, Rubens, and Bernini employed compositional tools—including exaggerated perspective, directional light (chiaroscuro), and orchestrated figural gesture—to guide the viewer’s eye and evoke psychological or spiritual intensity.

The Baroque approach emphasizes viewer orientation, narrative clarity, and visual hierarchy, making it a valuable historical precedent for representational artists concerned with attention guidance and pictorial impact. Its use of strong diagonals, spotlighting, and form articulation provides functional models for compositional directionality and spatial legibility.”

Bargue Plates / Bargue Drawing Course

“(Originally ‘Cours de Dessin‘) A 19th-century academic drawing curriculum developed by French artist Charles Bargue in collaboration with painter Jean-Léon Gérôme. Intended to serve as a preparatory training system for students entering formal academic art education, the course is composed of a progressive series of lithographic plates designed for direct replication.

A typical Bargue plate features a highly controlled linear and/or tonal rendering of a classical sculpture fragment, limb, or anatomical detail. Many of the plates include a breakdown of the form across multiple stages—beginning with simplified block-ins or envelope constructions, progressing through contour refinement, and concluding with fully rendered tonal versions. These plates are often characterized by their idealized form, simplified lighting, and high-contrast edge design, intended to help students develop visual discipline and an understanding of classical proportion and structure.

The Bargue Plates are typically executed in a sight-size method, requiring students to replicate the plates adjacent to the reference at a 1:1 scale. The method emphasizes contour fidelity, proportion accuracy, edge definition, and simplified value masses, with the goal of training perceptual control through disciplined visual comparison.

Within the Waichulis Curriculum, the use of Bargue Plates is not adopted as a core instructional component, as the curriculum emphasizes empirical perceptual-motor calibration, feedback-driven repetition, and hierarchical skill development rather than passive replication of fixed models. However, the curriculum does incorporate select Bargue plate delineations into the Shape Replication section as enhancers or strengtheners, particularly when a student would benefit from exposure to additional experience with curvilinear shapes, simplification strategies, or edge conventions present in the Bargue system. In such cases, the plates serve as a targeted challenge to support spatial fidelity, proportion assessment, and perceptual chunking within an otherwise adaptive and individualized learning trajectory.

While both systems value accuracy and control, the Waichulis Curriculum employs a dynamic, responsive methodology that fosters procedural fluency, perceptual awareness, and adaptive decision-making through calibrated visual tasks such as Shape Replication, Gradation Blocks, and Form Construction.

The Bargue Course remains widely used in academic ateliers, often as an introduction to classical draftsmanship, but its instructional model differs substantially from modern empirically informed training systems.”

Barrel Casing (Pencil Construction)

“The outer structural shell or housing of a pencil, typically cylindrical or hexagonal in shape, that encases the internal core material (such as graphite, charcoal, pastel, or colored pigment). The term ‘barrel’ is most commonly used when describing wood-cased pencils, mechanical pencil bodies, or woodless pencil shells that influence grip, ergonomics, and the mechanical stability of the marking core.

In wood-cased pencils, the barrel is usually made from cedarwood or other softwoods, which are lathe-cut and glued around the core. This casing provides rigidity for mark-making, protection for the fragile core, and a shaped surface for manual manipulation. In the Waichulis Curriculum, especially in the ANI LOD Drawing program, properly shaped and sharpened pencil barrels are crucial for achieving clean mark-making and maintaining pressure control​.

In mechanical or clutch pencils, the barrel refers to the entire body casing that houses the mechanical components, including lead advancement mechanisms and grip zones. Barrel shape and material (e.g., plastic, aluminum, or resin) can influence drawing precision and comfort.

In addition, pencils that become too short for a secure grip due to diminishing barrel length can be extended using a pencil extender—a tool that artificially lengthens the effective barrel, restoring ergonomic control without compromising function​.

Also, in contrast to ferrules (used in brushes), pencil barrel casings do not typically involve metal reinforcement unless part of a hybrid or mechanical design.

Lastly, some barrel casings are coated with varnish or lacquer finishes, which, while providing a smooth handling surface and aesthetic uniformity, may build up as residue on sharpener blades over time—particularly in electric or high-torque manual sharpeners. This can lead to blade dulling, reduced sharpening efficiency, and gumming, especially in fine-detail tools used in drawing programs.

The barrel casing serves both as physical protection and ergonomic interface. In academic drawing programs, particularly those emphasizing control and perceptual-motor calibration, the state of the pencil barrel is not merely incidental—it plays a role in maintaining consistent tool behavior and handling.”

Barrel Distortion

“A type of optical distortion in which straight lines bow outward from the center of an image, resembling the shape of a barrel. It is commonly produced by wide-angle lenses and results from radial magnification being greater at the image center than at the periphery. Barrel distortion affects geometric accuracy and must often be corrected in architectural or technical imaging.”

Base Level of Illumination

“The generalized level of light present in a scene or on a surface prior to the addition of direct light. It is determined by ambient light, reflected light, and environmental diffusion, and serves as the foundational tone upon which lighting structure is built. In perceptual terms, it represents the default visible state of forms under non-directional illumination.

Artists use this concept to establish a unified tonal environment, ensuring that forms relate consistently to one another even before direct light and resulting shadow structure is applied. In drawing and painting, failing to recognize the base level of illumination can result in overly contrasted compositions, disjointed spatial logic, or unrealistic form separations.

In the Waichulis Curriculum, awareness of base illumination plays a key role in value mapping, gradation structure, and light logic exercises, providing a perceptual and procedural framework for layering direct light, reflected light, and occlusion effects. It is not a literal measure, but a strategic construct used to maintain coherence in value relationships and environmental believability.”

Basis Size (Paper)

“The standardized, uncut sheet dimensions established by industry conventions to determine the weight classification of a specific type of paper. In the pound-based system (commonly used in the United States), paper weight is calculated as the total weight of one ream (500 sheets) of paper measured at its basis size, not necessarily the finished size sold to consumers.

Basis sizes vary depending on the category of paper and are fixed industry standards, not subject to individual determination. For example, bond paper typically uses a basis size of 17 x 22 inches, while Bristol board uses 22.5 x 28.5 inches. As a result, two papers rated with the same numerical pound weight may differ significantly in actual thickness, density, or stiffness if their basis sizes differ.

Understanding basis size is essential for accurately interpreting paper weight specifications, comparing materials across categories, and selecting appropriate substrates for specific artistic, archival, or printing needs.”

Bauhaus

“A German art and design school founded by Walter Gropius in 1919, which operated until 1933. The institution merged fine art, craft, and industrial design into a unified pedagogical framework grounded in functionalism, material honesty, and visual economy. Its foundational course (Vorkurs) emphasized the analysis of form, color, material properties, and spatial relationships before specialization—setting a precedent for systematic skill development in art education.

While the Waichulis Curriculum differs in structure and emphasis, it shares the Bauhaus focus on perceptual calibration, procedural fluency, and hierarchical skill acquisition. Both systems reject ornament for its own sake, advocating instead for intentional design and operational clarity. Bauhaus innovations continue to influence contemporary approaches to composition, simplification, and material interaction across disciplines ranging from architecture to visual communication.”

Beauty

“A multifaceted concept encompassing perceptual, cognitive, and emotional responses to stimuli that are perceived as aesthetically pleasing, harmonious, or skillfully organized. In philosophical aesthetics, beauty has been variously described as an objective quality (Plato), a subjective judgment (Hume), or a product of disinterested pleasure (Kant). Modern empirical and evolutionary aesthetics extend these frameworks by considering perceptual mechanisms, cultural context, and adaptive function.

Denis Dutton’s evolutionary perspective in The Art Instinct frames beauty as a cross-cultural signal shaped by natural and sexual selection, grounded in human evolutionary history. According to Dutton, aesthetic preferences—including those for symmetry, complexity, and virtuosity—are not arbitrary but reflect evolved psychological adaptations that historically contributed to mate selection, environmental assessment, and social cohesion. He identifies traits such as skill display, imitation, and emotional expressiveness as universal aesthetic signals, often bundled into what cultures recognize as ‘beauty’​.

Contemporary neuroaesthetics supports the notion that beauty judgments engage brain systems related to reward, attention, and pattern processing. These judgments can be influenced by factors like symmetry, proportionality, novelty, and cultural familiarity. However, beauty is not reducible to a fixed set of properties—it emerges through interaction between stimulus structure, cognitive architecture, and sociocultural conditioning.

While the specifics of what is deemed beautiful may vary across cultures and time periods, the cognitive and perceptual architecture that produces beauty responses appears to be universally distributed. Beauty, therefore, is not merely a cultural construct or personal preference, but a biologically grounded, evolutionarily shaped evaluative mechanism with deep psychological resonance.”

Beeswax

“A natural wax secreted by honeybees, used extensively in painting mediums for its stabilizing, textural, and preservative qualities. Available in two principal forms—natural yellow and refined white—beeswax is typically chosen for art applications in its bleached, purified state due to its lighter color and slightly firmer consistency. It melts between 63–66°C and can be safely liquefied in a water bath, though care must be taken to avoid overheating, which can cause darkening.

In painting, beeswax is most commonly employed in wax mediums, encaustic painting, and certain emulsions. When incorporated into a painting medium—such as the Maroger Italian Wax Medium favored in the Waichulis Curriculum—it contributes to a thicker, more controllable consistency, speeds drying, and emits little to no odor​. It is often combined with natural resins (e.g., damar, rosin) and solvents (e.g., turpentine) to produce malleable painting compounds with varying degrees of gloss, adhesion, and hardness​.

Beeswax is also valued in conservation contexts. Wax-resin adhesives composed largely of beeswax have historically been used in canvas relining for their moisture resistance and compatibility with aged paint films. In tempera and wax emulsion systems, beeswax can be saponified (made into a soap) and combined with casein, egg, or gums for specialized applications. However, improper saponification or excess alkali can result in yellowing or unstable films​.

While beeswax offers excellent resistance to moisture and air, its mechanical durability is lower than that of resins or oils. It should be used thoughtfully in formulations requiring flexibility, matte effects, or burnishable surfaces.”

Bevel (Matting/Framing)

“A cut made at an angle—typically 45 degrees—along the inner edge of a mat board window to expose a sloped surface of the mat’s core. This beveled edge serves both aesthetic and practical purposes: it creates a visual transition between the artwork and the mat, enhancing the sense of depth and directing visual attention inward, and it prevents the mat from casting a harsh shadow or overlapping the artwork unevenly.

Bevel cuts are typically made using a specialized mat cutter with a blade set at an angle. The core of most archival mat boards is white or off-white, though black-core and other colored variants are also available for visual contrast. The bevel must be clean and precise to maintain a professional appearance and prevent fraying or fiber separation over time. In archival framing, bevel cuts should be made on acid-free, lignin-free boards to avoid long-term chemical degradation of the artwork.”​

Bias

“A cognitive or perceptual tendency that systematically deviates from neutrality, often as a result of prior experience, contextual influence, or neural predisposition. In the visual arts, bias can affect everything from color perception and form interpretation to representational accuracy and aesthetic judgment.

Perceptual biases are not errors in themselves—they are adaptive mechanisms that prioritize efficiency over veridicality. For example, light-from-above or face-detection biases increase processing speed in common environments but may lead to misinterpretations in atypical contexts. Cognitive biases—such as confirmation bias, anchoring, or the familiarity heuristic—can influence decision-making in critique, material choice, or subject selection.

In perceptual training, recognizing and accounting for both perceptual and cognitive biases is critical to refining observational accuracy and avoiding distortions that masquerade as ‘natural’ seeing.”

Binary

“A descriptor indicating a system, classification, or representation limited to two discrete states or values—commonly denoted as 1/0, yes/no, true/false, or on/off. In perceptual science, binary distinctions often refer to categorical frameworks where entities are either included or excluded without allowance for gradation (e.g., a figure is either a triangle or it is not). This classical approach, grounded in Aristotelian logic, contrasts with graded or fuzzy systems that permit degrees of membership. In visual cognition and shape representation, binary features may define the presence or absence of attributes (e.g., symmetry present vs. absent), although more recent theories favor continuous or probabilistic models that better reflect neural processing and perceptual variability.”​

Binder

“A substance that holds pigment particles together, influences the working properties of a medium, and contributes to its adhesion to a surface, forming a cohesive and durable paint or drawing material. Beyond cohesion and adhesion in both wet and dry materials, binders regulate the viscosity, drying time, flexibility, and durability of the medium, significantly affecting how it handles and ages over time.

In wet media, such as oil, acrylic, watercolor, and tempera, binders form a continuous film that encapsulates pigment particles, ensuring adhesion, stability, and often a specific surface sheen. Some binders, like linseed oil in oil paint, undergo oxidation and polymerization, creating a flexible yet durable paint film over time. Acrylic polymer emulsions dry through the evaporation of water, forming a resilient and water-resistant film, while gum arabic, used in watercolor, allows for re-wettability and smooth pigment dispersion.

In dry media, including pastels, charcoal, and compressed graphite, binders function as weak adhesives that maintain cohesion within the material while allowing for effective mark-making. The proportion and type of binder used influence hardness, erasability, and pigment release. For example, a higher binder ratio in graphite pencils results in a harder core, while a lower binder content in soft pastels allows for far greater graphite deployment.

Additionally, some binders contribute to optical qualities such as gloss, transparency, or matte finishes. Egg yolk in tempera, for instance, produces a semi-matte, luminous surface with a brittle yet durable structure. Mayer emphasizes that binders must be carefully chosen based on their chemical stability and interaction with pigments to ensure long-term preservation and performance of the artwork​.”

Binocular Depth Cue

“A category of depth information derived from the slight differences between the light patterns projected onto each retina due to the horizontal separation of the eyes (binocular parallax). Binocular depth cues require input from both eyes and primarily include:

Binocular Disparity (Stereopsis): The relative lateral displacement between the left and right retinal images of the same object, used to infer relative depth. The magnitude of disparity signals how near or far an object is in relation to the fixation point. This cue is most effective within a range of approximately 30 meters.

Convergence: The inward turning of the eyes to fixate on a nearby object. The degree of convergence is used as an oculomotor cue to infer absolute depth for close-range stimuli (effective up to ~10 meters).

Shadow Stereopsis: Perceived depth that can result from binocular differences in luminance or shading information—not positional disparity—allowing for a sense of three-dimensional form even when geometric disparity is minimal or absent.

These cues operate in tandem with or independently of monocular cues to construct a perception of three-dimensional space. Binocular disparity provides relative depth information, while convergence provides absolute depth for objects close to the observer. The perceptual system can integrate these signals to compute a depth map through cue interaction and promotion mechanisms.”​

Biomorphic

“Shapes or forms that visually evoke the shapes, structures, or growth patterns of living organisms—without necessarily directly representing specific biological entities. These forms typically exhibit curvilinear contours, asymmetry, and non-geometric fluidity, distinguishing them from mechanical or architectonic elements.

In representational and abstract art, biomorphic elements are often used to introduce a sense of natural movement, visual rhythm, or associative resonance with organic life.”

Bit Depth

“A digital imaging term that refers to the number of bits (binary digits: the smallest units of digital information, representing a value of 0 or 1) used to represent the color or tonal information of a single pixel. Bit depth determines the range of possible values a pixel can hold, directly influencing how many distinct shades or colors can be displayed. For example, an 8-bit image allows for 2⁸ (256) levels per channel, while a 24-bit RGB image (8 bits per red, green, and blue channel) supports over 16 million color combinations.

In grayscale imaging, bit depth defines tonal resolution; in color images, it defines color fidelity. Higher bit depths enable smoother gradations and reduce banding, which is particularly important in applications like digital painting, high-end photography, and print reproduction. However, increasing bit depth also raises file size and computational load.

In perceptual terms, human vision is more sensitive to luminance than to chromatic detail, and research suggests that most people cannot perceive differences beyond 10–12 bits per channel under normal viewing conditions. As such, while 16-bit formats (65,536 levels per channel) are common in professional workflows to preserve editing latitude, final display formats often use 8-bit per channel as a practical standard.”​

Black Oil

“A historical and chemically modified oil painting medium composed of linseed oil that has been cooked with litharge (lead monoxide). The lead acts as a powerful metallic drier, significantly accelerating the oxidative polymerization of the oil and altering its rheological and handling properties. The resulting black oil is typically darker, thicker, and more viscous than untreated linseed oil, and forms a highly flexible and fast-drying film.

Black oil is traditionally produced by boiling raw or cold-pressed linseed oil with litharge (PbO)—a process that saturates the oil with lead ions. This interaction facilitates the formation of lead soaps, promoting faster drying and enhanced flexibility in the resulting paint film. The mixture may range in color from amber to deep brown depending on the oil’s condition and exposure to heat and oxygen. Chemical Reaction Summary:

Linseed Oil + PbO (Litharge) → Lead-Modified Oil (Black Oil)

Lead compounds act as oxidative catalysts, improving drying without requiring additional siccatives (metallic drying agents that accelerate the polymerization of oils).

Black oil has been used since the Renaissance and is a central component of Maroger’s Medium, a 20th-century revival of ‘Old Master’-style oil-resin emulsions. In traditional painting, black oil was employed to: increase gloss and flow for glazing and fine detail, speed drying time of layers, improve adhesion and film integrity over time, and enhance the flexibility of oil paint to reduce cracking. It was frequently combined with natural resins (like mastic or damar) and waxes to form ‘gel mediums’ or megilps, prized for their buttery texture and optical clarity.

Despite its historical use, black oil has significant conservation risks. The introduction of lead accelerates drying but also increases the risk of darkening or embrittlement over time, contributes to potential chemical instability when layered improperly (e.g., fat-over-lean violations), and is toxic upon ingestion or prolonged dermal exposure due to the presence of lead compounds.

Modern conservation practice often discourages the use of lead-modified oils unless there is a historically informed rationale and full awareness of the risks involved. While black oil forms a durable film when correctly used, the irreversibility of its effects and the toxicity of its components make it a non-standard material in contemporary archival painting systems.

Though less common in many contemporary atelier training programs, black oil continues to be actively employed within the Waichulis Curriculum as a component of Maroger’s Italian Wax Medium. In this context, its handling properties—such as improved flow, flexibility, and drying control—are valued for layered indirect painting techniques and glazing strategies. The medium, when properly prepared and used with informed technique, provides a buttery, satin-bodied consistency ideal for a specific type of maintaining control over mark-making and surface development. While black oil contains lead and carries documented toxicological and conservation considerations, its use within the curriculum is intentional and carefully contextualized, reflecting both historical precedent and modern studio standards. The decision to use such a medium rests on informed practice and deliberate control—not on traditionalism or convention.”

Blanching

“(Also referred to as bloom) The formation of a whitish, foggy, or milky appearance on the surface of a painting or varnish layer. This condition typically results from the absorption of moisture, exposure to cold solvents, or thermal disruption that causes microstructural changes in the varnish or paint film. The effect occurs when microscopic voids—such as trapped moisture or air—scatter incident light, disrupting the surface’s optical clarity and creating a hazy or frosted visual effect.

Blanching most often affects natural resin or synthetic varnishes but can also occur in wax coatings or paint films. The phenomenon significantly reduces gloss, color saturation, and the perceived depth of the varnish layer, compromising both aesthetic presentation and archival stability.

While the term ‘bloom’ is sometimes used interchangeably with blanching, especially in conservation texts, some sources reserve bloom to describe blanching caused specifically by moisture absorption, whereas ‘blanching’ may also include heat- or solvent-induced haze. However, in many practical contexts—especially in studio and museum settings—the two terms are functionally synonymous.

Importantly, blanching is a physical, not chemical, alteration. Unlike pigment fading or chemical degradation, blanching is often reversible through reactivation of the varnish with mild solvent vapor, heat, or reapplication of a compatible coating.”

Bleaching

“The chemical fading or discoloration of pigments, dyes, or support materials due to exposure to light (particularly UV radiation), oxidation, or reactive chemical agents. Unlike blanching, which affects the optical clarity of surface films, bleaching involves the irreversible breakdown of chromophores—the molecular structures responsible for color—leading to permanent loss of chromatic intensity or a shift in hue.

Bleaching can occur in a wide range of materials, including organic pigments, textile dyes, paper, and photographic emulsions. It is often accelerated by sunlight or strong artificial light, especially when UV protection is lacking, ozone or other airborne oxidizers, acidic environments, or the use of strong cleaning or restoration chemicals.

Once bleaching has occurred, it is typically not correctable, as the colorant itself has been structurally degraded or destroyed. This makes lightfastness testing and archival material selection essential in any practice concerned with long-term stability.”

Blending

“The act of optically or physically merging adjacent values, colors, or edges to produce a smooth, transitional gradient across a pictorial surface. In the Waichulis Curriculum, blending is taught as a controlled application of material—distinct from tool-based smudging or surface rendering aimed at concealing marks.

In the Waichulis Curriculum’s Language of Drawing, blending is achieved through pressure modulation, stroke tapering, and layering techniques using materials like uncompressed charcoal and white pastel. External tools such as tortillons or smudgers are deliberately avoided, as they compress the paper’s tooth and diminish the artist’s control over material behavior and mark structure.

In the Waichulis Curriculum’s Language of Painting, blending may involve wet-into-wet application, feathering, edge tapering, and brush modulation to facilitate smooth transitions between forms or value zones. The use of mediums can support extended working time to aid these transitions. However, blending in painting does not require the complete removal of brushstrokes; rather, it prioritizes structured modulation that supports form and clarity.

Blending differs from rendering, which typically emphasizes surface refinement through the removal or minimization of visible marks. While blending contributes to cohesion and transition, it does so without negating the communicative role of stroke direction, edge quality, or material behavior.”

Block-In

“The initial stage of a drawing process in which major shapes, proportions, and placements are established using simplified lines and value masses. It serves as the structural foundation of a drawing, allowing the artist to organize compositional elements, measure relationships, and establish primary orientation and scale before committing to more refined rendering or detailing.

In the Waichulis Curriculum, the block-in phase emphasizes accuracy over finish—it is where the artist translates the visual field into a controlled framework of shapes, boundaries, and spatial relationships. This stage is typically executed with soft, easily alterable materials like charcoal, and is developed with a light touch to preserve the working surface for subsequent layering and refinement.

While block-in is most often used in reference to drawing, its conceptual role has a close analogue in painting, where a similar foundational structure is sometimes referred to as the lay-in. Though the terms are occasionally used interchangeably, especially outside of strict curriculum contexts, block-in is best reserved for the initial drawing phase, whereas lay-in denotes the analogous early paint application stage, where large masses and general color/value zones are introduced.

Both stages share the goal of establishing a stable framework before detailed development, but they differ in media behavior, layering strategies, and tool dynamics.”

Bloom

“A range of visual phenomena that share the appearance of a soft, cloudy, or diffuse effect—arising from physical, chemical, or perceptual conditions. In art, the term has multiple domain-specific meanings:

Perceptual Bloom (Visual Spillover): In visual perception, bloom refers to the glow-like spill of high-intensity luminance around a bright target. This phenomenon results from a combination of optical and neural processes, including light scatter within the eye, veiling glare, and cortical enhancement mechanisms in early visual processing. Perceptual bloom contributes to the experience of glare, luminosity, and atmospheric diffusion—particularly around highlights or emissive light sources observed against darker surroundings.

In image-making, artists may simulate bloom effects to evoke brilliance, intensity, or spatial depth by extending light zones beyond their physical boundaries, softening transitions, and reducing local edge definition. This painterly strategy enhances the viewer’s impression of radiant light behavior—especially in depictions of glass, metal, flame, or backlit translucency.

Importantly, bloom should be distinguished from halo effects: A halo is typically a localized glow around a highlight or edge, achieved through subtle value compression and restrained contrast, often used to enhance reflectivity or luminous intensity on a surface. A bloom, by contrast, is generally larger in scope, less defined, and evokes a more immersive and ambient luminance—suggesting actual light emission or strong environmental diffusion.

Where halos function to accentuate or frame a highlight, blooms tend to submerge form boundaries and dissolve structural clarity, heightening the illusion of emitted or overwhelming light. Both phenomena exploit known perceptual behaviors but differ in scale, structure, and intended narrative function.

Varnish Bloom (Surface Clouding): In painting conservation and materials science, bloom refers to a cloudy, whitish, or foggy haze that can appear on the surface of a dried varnish film. This phenomenon is typically caused by moisture contamination during the drying or curing process, especially in humid environments. When varnish is applied under conditions of high ambient humidity or poor ventilation, moisture from the air can become trapped within the upper layers of the drying varnish film. These trapped water droplets scatter light, leading to a diffuse, milky appearance. This is the most common cause of varnish bloom and is primarily a subsurface effect, not something that merely rests on the surface.

Although less frequently, surface bloom can also occur when condensation forms on the varnish after it has dried, especially in the case of hygroscopic (absorbs moisture from the air) natural resins like mastic. In such cases, the bloom may be superficial and removable through gentle polishing or reapplication of solvent to even the surface. However, if moisture was introduced during the curing process, the effect is often locked into the film and may require full removal and revarnishing.

Bloom is most common in natural resin varnishes (e.g., mastic, damar) and is exacerbated by thick application, poor solvent ratios, or inadequate drying conditions. To avoid bloom, varnishes should be applied in thin, even coats in a well-ventilated, low-humidity environment and allowed to cure fully without obstruction. Synthetic varnishes (e.g., acrylic or alkyd-based) are generally more resistant to bloom, but not entirely immune under extreme conditions.

Colored Pencil Bloom (Wax Migration): In colored pencil work, bloom refers to the white or foggy layer that can appear on the surface of heavily burnished drawings. This effect is caused by the migration of wax-based binder components to the drawing’s surface over time. It is more prevalent in wax-heavy pencils and under high ambient temperatures or pressure. Though largely cosmetic, bloom can be reduced or removed by gentle buffing or the application of fixative.”

Bloom’s Taxonomy

“A hierarchical classification of cognitive skills used to define and assess educational objectives. Developed in 1956 by educational psychologist Benjamin Bloom and colleagues, the taxonomy organizes learning into a progressive framework ranging from basic recall to complex synthesis and evaluation. Its original six cognitive levels are:

Knowledge – Recall of facts and basic concepts

Comprehension – Understanding meaning or interpretation

Application – Using knowledge in new situations

Analysis – Breaking down information into parts and examining relationships

Synthesis – Compiling information to create new structures or patterns

Evaluation – Judging the value of information or decisions based on criteria

A revised version (2001) restructured these categories into: Remember, Understand, Apply, Analyze, Evaluate, and Create, shifting the focus from nouns to action verbs to better represent dynamic cognitive processes.

In the context of skill-based training, Bloom’s Taxonomy is often used to design curricula that guide learners from foundational understanding toward higher-order thinking, including problem-solving, adaptation, and creative integration. The taxonomy emphasizes that expert-level performance involves more than rote memory—it requires the ability to flexibly apply, analyze, and reconfigure knowledge.

The Waichulis Curriculum reflects this educational model by calibrating exercises to move learners through increasing levels of complexity. Early tasks focus on perceptual encoding and replication (aligned with ‘Remember’ and ‘Understand’), while later stages engage strategic execution and expressive problem-solving (aligned with ‘Analyze’ and ‘Create’). This approach ensures that students not only acquire technical competencies but also develop the cognitive fluency necessary for adaptable, intentional visual communication.”

Blue Wool Scale

“A standardized method for assessing the lightfastness of dyes and pigments by comparing their fading behavior to that of blue-dyed wool samples exposed to light. Originally developed in the early 20th century for the textile industry, it has since been adopted in fields such as printing, conservation, and fine art to evaluate the permanence of colorants under light exposure.

The concept of using blue-dyed wool to measure fading dates back to 1914 in Germany, with formal standardization occurring approximately 20 years later through the efforts of the Society of Dyers and Colourists. The term ‘Blue Wool’ refers to the eight strips of wool fabric, each dyed with a specific blue dye known to fade at a predictable rate. These strips serve as a reference to gauge the lightfastness of other materials by comparison.

In practice, a sample of the material to be tested is exposed to light alongside the Blue Wool standard card for a set period. After exposure, the degree of fading in the sample is compared to the fading observed in the Blue Wool strips. The sample is then assigned a Blue Wool rating from 1 to 8, where 1 indicates very poor lightfastness (extremely fugitive) and 8 denotes excellent lightfastness (highly permanent). This comparative method enables the consistent evaluation of lightfastness across various materials and conditions.

Artists and conservators utilize the Blue Wool Scale to ensure the longevity of artworks. Materials with higher Blue Wool ratings are preferred for works intended to endure prolonged light exposure. The scale’s standardized approach provides a reliable means to assess and compare the lightfastness of various pigments and dyes, aiding in the selection of materials for both creation and preservation purposes. Schmincke, a German manufacturer of artists’ materials, utilizes the Blue Wool Scale as the foundation for its own lightfastness rating system. However, instead of using the numerical 1–8 scale directly, Schmincke translates these ratings into a five-star system to make the information more accessible to artists. In this system, a higher number of stars corresponds to better lightfastness, aligning with higher numbers on the Blue Wool ScaleTherefore, while the Schmincke scale is not identical to the Blue Wool Scale, it is derived from it and serves the same purpose of informing artists about the lightfastness of their materials.”

Body of Work

“A cohesive collection of artworks produced by an individual over time that collectively reflects their thematic concerns, technical development, aesthetic priorities, and conceptual evolution. A body of work is not merely an accumulation of pieces, but a curated ensemble that demonstrates continuity, progression, or variation in form, content, and intent.

Philosophically, the notion of a ‘body of work’ aligns with the idea of artistic identity as an emergent property—formed through persistent exploration within formal, cultural, or expressive frameworks. It allows both viewers and critics to assess an artist’s trajectory, recurring motifs, or innovations relative to broader aesthetic traditions or historical contexts.

From an evolutionary aesthetics perspective, as discussed by Denis Dutton, a coherent body of work may serve as a signal of artistic intentionality, creative intelligence, and skill display—qualities that contribute to cross-cultural recognition and artistic legacy​. The perceived individuality and consistency within a body of work often play a role in establishing artistic credibility and long-term cultural significance.

Within pedagogy, the construction of a body of work represents a shift from isolated exercises to sustained thematic and procedural fluency, reflecting increasing artistic autonomy and conceptual clarity.”

Bokeh

“A term derived from the Japanese word boke (blur or haze), referring to the aesthetic quality of the out-of-focus areas in a photographic or optically simulated image. While the term is often colloquially used to describe the visible soft discs seen in background highlights, these discs are more precisely called circles of confusion—the result of point light sources rendered out of focus due to falling outside the lens’s depth of field.

Bokeh refers not to the discs themselves, but to how those discs—and the blur more generally—are perceived. Factors such as edge softness, brightness falloff, aperture shape, and lens aberrations influence whether the bokeh is considered ‘pleasant’ (e.g., smooth and diffuse) or ‘distracting’ (e.g., harsh, ringed, or polygonal).

In short, the circles of confusion are the optical cause, while bokeh is the perceptual and aesthetic effect.”

Bole Surface

“A specially prepared, colored underlayer—traditionally composed of a fine clay (bole), water, and animal glue—applied over a gessoed ground to receive and enhance gold or silver leaf during water gilding. Bole provides both a smooth substrate and an optical foundation that enriches the appearance of the metal leaf applied over it.

Traditional bole is a natural red or yellow earth pigment, primarily composed of iron oxide-rich clays. It is mixed with a gelatin solution (commonly rabbit-skin glue) to create a creamy, easy-brushing consistency. This mixture is then applied in thin, smooth layers onto an already prepared gesso ground and meticulously sanded between applications​.

The function of a bole surface is:

The use of bole in gilding techniques dates back to antiquity but became particularly codified during the Medieval and Renaissance periods. Artisans of the Gothic and Early Renaissance periods often applied multiple, finely sanded coats of red bole before gilding altarpieces, manuscript illuminations, and religious icons. Bole surfaces were integral to the highly burnished gold backgrounds seen in works from schools such as Siena and Florence​.

While a gesso surface alone can receive gilding, bole provides superior burnishability and optical warmth. It is essential for achieving the true brilliance and depth associated with water gilding.”

Bounce Light

“Illumination that reaches a subject indirectly after reflecting off another surface, such as a wall, floor, ceiling, or adjacent object. Unlike direct primary or secondary light sources, bounce light is the result of the scattering and diffusion of light, producing softened, often less intense illumination across shadowed regions.

In perceptual training and representational image-making, bounce light plays a crucial role in modulating shadow masses, revealing subtle form information within otherwise occluded areas, and creating smoother spatial transitions. Bounce light is often the primary generator of the reflected light observed within a form’s value structure, where secondary illumination lifts the darkness of the form shadow without overpowering the primary light’s overall control.

Bounce light differs from fill light in that it is not usually an intentionally placed secondary source; rather, it is an environmental consequence of light interaction within a space. While it can enhance form articulation and spatial atmosphere, bounce light must be carefully controlled or selectively interpreted to avoid undermining the dominant structure established by the primary light source.

Effective management of bounce light supports chiaroscuro modeling, atmospheric modulation, and the construction of spatial depth without confusing light directionality or form hierarchy.”

Boundary Box

“A rectangular or square perimeter used to establish spatial limits and proportional reference points for a drawing or painting. The boundary box helps to contain, organize, and position elements within a composition, ensuring accurate placement, scale, and alignment relative to the intended pictorial space. This structure serves as an essential guide for mapping forms, maintaining proportional integrity, and controlling spatial relationships throughout the creative process. The concept of the boundary box is first introduced in the Shape Replication exercises in the Waichulis Curriculum.”

Bounding Contour

“The outermost edge of a shape or form that defines its silhouette and spatial boundaries.”

Bozzetto

“(Plural: bozzetti) An Italian term meaning ‘small sketch’ or ‘rough model,’ used in the visual arts to refer to a preliminary, small-scale three-dimensional study—typically executed in clay, wax, or plaster—created to explore ideas for a larger sculpture or complex composition. Bozzetti are characterized by their spontaneity, expressive handling, and informal resolution, often serving as a means to rapidly visualize a form, pose, or compositional structure before refinement.

Originating in the Italian Renaissance, the bozzetto was widely employed by artists such as Michelangelo, Bernini, and Canova, offering a flexible medium for testing design concepts and spatial arrangements. In many cases, bozzetti were used as private studio tools—not necessarily intended for client presentation—though they are now valued as critical insights into an artist’s creative process.

While primarily associated with sculpture, the term may also be applied to rough preparatory oil sketches or conceptual studies in painting, when they serve a similar generative function prior to more formal planning.

Although both bozzetto and modello refer to preparatory works, they differ significantly in intent and finish. A bozzetto is typically rough, informal, and executed early in the process to explore foundational ideas. In contrast, a modello is usually a more polished, resolved study, often created to present to a patron for approval or to serve as a visual contract for the final work. While a bozzetto captures the gestural exploration of a concept, a modello presents a more refined and representative version of the intended outcome.

Bozzetti are thus valued for their immediacy and expressive energy, serving as a tangible trace of an artist’s evolving thoughts, while modelli represent a later stage in the development pipeline, often positioned closer to the execution phase.”

Brace

“A structural support affixed to the rear of a panel (often as part of a larger framework or cradling system) designed to combat warpage, twisting, and other dimensional changes over time. Braces are typically composed of well-dried wood strips and can be arranged in horizontal, vertical, or diagonal orientations depending on the size and material of the panel. They are secured using strong adhesives, such as casein or hot hide glue, and may be mortised, dovetailed, or otherwise joined for stability. When integrated into a complete framework with cross-members, the system may be referred to as ‘cradling.’

In conservation and panel preparation, braces ensure rigidity, increase resistance to environmental stressors, and provide a more stable substrate for gesso and paint layers. The choice of brace configuration must consider the panel’s expected expansion or contraction to prevent buckling or stress fractures in the ground or paint film.”​

Bracketing Method

“A systematic approach to refining a color mixture by producing deliberate variations that surround a target hue in perceptual space. Brackets typically include lighter, darker, warmer, and cooler iterations relative to the mixture-in-progress. This comparative process allows the artist to evaluate subtle shifts in value and chroma side-by-side and iteratively converge on a more accurate or expressive match.

Simply speaking, you bracket a color by mixing two colors of the same value, but different hues, one hue on one side of your target color and one on the other—such as a red-orange and a yellow-orange to bracket an orange target. By mixing between these two bracketed colors, the artist can narrow in on the precise hue more efficiently than through trial-and-error. This strategy controls for value while isolating hue variation, preventing the cascading errors that often occur when mixing without structured reference points.

The method aligns with perceptual learning strategies that emphasize calibration through feedback, contrast, and fine-tuning—promoting deliberate control over the inherently relative nature of color perception.”

Brads (Framing)

“Slender, often headless nails or fasteners used in the process of picture framing to secure artworks, glazing, backing boards, or mats within a frame. Most commonly employed in combination with a point driver or inserted manually, brads serve to hold the layered assembly of a framed artwork in place without causing significant damage or warping to the materials.

In contrast to flexible points or more adjustable framers’ tabs, brads are generally rigid and semi-permanent once installed, offering a higher degree of security but reduced flexibility for future adjustments. They are typically made of metal (e.g., steel or brass) and vary in length and gauge to accommodate different frame depths and substrate combinations.

From a conservation standpoint, the use of brads must be carefully considered. Improper placement or excess pressure can lead to stress on the artwork or glazing, especially in the case of paper-based media where brads may inadvertently contact or compress the substrate. For this reason, professional framers often employ barrier layers (e.g., archival foam core or spacers) between the artwork and the brads, ensuring physical separation and minimizing risk of abrasion, puncture, or acid migration.

Brads are most effective in wood frames where they can be driven into the rabbet (the recessed interior edge) to lock contents securely. Their use may also be supplemented or replaced by friction-fit systems, tension clips, or archival-quality framing points depending on conservation goals, material sensitivity, and ease of reversibility.

Understanding the mechanical role of brads is essential for any artist or preparator seeking to safeguard an artwork’s structural integrity during presentation or storage. While brads provide a straightforward and cost-effective solution for securing framed elements, their application should always align with best practices in archival framing and preventive conservation.”

Brand / Branding (Artistic Context)

“The process by which an artist develops and maintains a recognizable identity or thematic presence across their body of work, public persona, and professional materials. Branding in art involves the deliberate or emergent coordination of aesthetic choices, subject matter, messaging, and presentation to create a cohesive impression that distinguishes the artist within a cultural or market context.

While related to style (which is typically an emergent property of process), branding is more externally constructed and strategic—often involving choices about how the work is marketed, what narratives are emphasized, and how the artist is positioned in relation to institutions, audiences, or social movements.

Effective branding may include consistent visual motifs, conceptual frameworks, or even specific modes of communication (e.g., titles, artist statements, social media presence). In contemporary art discourse, branding is sometimes critiqued for conflating artistic identity with commercial appeal. However, from an empirical and cognitive standpoint, branding can function as a heuristic for categorization and recognition, enabling more efficient communication of artistic intent and thematic coherence.

In practical terms, an artist’s brand serves as an interface between creator and audience—facilitating access, expectation, and interpretive framing.”

Breach (Drawing Surface)

“The physical compromise of the paper’s surface integrity, characterized by the breakdown of sizing and the exposure of inner fibers or pulp. It often presents as visible fuzziness, thinning, or transparency in the paper. Breached areas may absorb material unpredictably, reject dry media entirely, or become prone to tearing. Common causes include over-erasure, repeated abrasion, or excessive localized pressure.”

Unlike a burnish, which compresses but does not remove surface texture, a breach indicates a loss of surface material and marks a more serious compromise of the drawing substrate. Preventing breaches requires careful pressure control and awareness of surface tolerance—especially during corrective processes or high-saturation applications.”

Bridging Marks

“Transitional strokes or lines that connect separate areas within a composition, facilitating visual flow and unity between distinct elements.”

Brightness

“A perceptual attribute describing the apparent intensity of light emitted or transmitted by a source, or reflected from a surface, as experienced by an observer. Unlike lightness, which pertains to apparent reflectance, brightness refers to the overall magnitude of perceived light energy reaching the eye (sometimes simplified as ‘apparent luminance’). While the CIE defines brightness as ‘the attribute of a visual sensation according to which an area appears to emit more or less light,’ modern vision science refines this to emphasize its dependence on absolute luminance, spatial context, contrast adaptation, and neural processing mechanisms. Brightness perception is influenced by surrounding light levels (e.g., the Bartleson-Breneman effect) and can be subject to illusions, such as simultaneous brightness contrast and the Craik-O’Brien-Cornsweet illusion. In applied disciplines, brightness is a key factor in display technology, illumination engineering, and vision research, where it is often measured in candelas per square meter (cd/m²) to quantify luminous intensity objectively.”

Bristle

“The coarse, stiff hair used in the construction of certain types of paintbrushes—most commonly sourced from hogs (white or Chungking bristle)—favored for their durability, spring, and ability to carry and manipulate heavier-bodied media such as oil paint. Natural bristles are distinguished by their split ends (flags), which enhance paint retention and allow for expressive, textured applications. Bristles resist deformation, enabling aggressive brushwork without significant degradation.

Bristle brushes are typically used for initial paint application, scumbling, and gestural blocking due to their high resistance and capacity to hold a substantial volume of paint. They are often contrasted with synthetic or sable brushes, which offer lower resistance and finer blending properties. Proper cleaning and care are essential to preserve the natural flag structure and avoid splaying, particularly near the ferrule where residual paint can accumulate and damage the bundle’s alignment​​.”

Bristol Board

“A heavyweight, multi-ply drawing and illustration surface made from highly compressed, quality paper layers bonded into a stiff, smooth sheet. Originally developed in Bristol, England (from which it takes its name), it is valued for its rigidity, surface consistency, and compatibility with a range of media—including graphite, ink, colored pencil, marker, and airbrush. There are two primary surface finishes:

Plate (Hot-Pressed): Extremely smooth and virtually textureless. Ideal for fine pen-and-ink work, technical drawing, and detailed rendering where minimal drag or grain is desired.

Vellum (Cold-Pressed): Slightly toothier with a soft texture, offering better grip for dry media like graphite, charcoal, or colored pencil.

Bristol board is typically available in 2-ply, 3-ply, or 4-ply thicknesses, providing a firm support that resists buckling under erasure or layering, but is not generally recommended for wet media due to its lower absorbency compared to watercolor-specific papers.

In the Waichulis Curriculum, while mid-toned, toothy paper is often preferred for charcoal-based exercises, Bristol board may be introduced in specific contexts—such as value control with graphite or contour-focused shape exercises—where surface stability and resistance to distortion are prioritized. However, due to its brightness and surface density, Bristol is not suitable for uncompressed dry media that rely on open tooth for adhesion.

As with all supports, Bristol board should be acid-free if long-term durability is a concern, and artists are advised to distinguish between true archival grades and those marketed as ‘artist-grade’ without substantiating data.”

Brunaille

“A monochromatic painting executed entirely or predominantly in brown colors—typically using earth pigments such as raw umber, burnt sienna, or sepia. Like grisaille (gray-scale) and verdaille (green-scale), brunaille is part of a historical tradition of value-dominant painting where chromatic complexity is intentionally suppressed.

The aim of brunaille is to isolate value structure, edge behavior, and spatial hierarchy without the additional perceptual demands of full chromatic composition. This controlled limitation allows artists to focus on the calibrated modulation of light and form, refining their understanding of chiaroscuro, volume, and composition.”

Brush (Paintbrush)

“A hand-held tool used in painting to apply, manipulate, or remove material from a surface. It typically consists of the following components:

Handle: The rigid grip portion of the brush, usually made of wood or acrylic. Length and thickness vary based on brush type (e.g., short handles for control in detail work, long handles for gestural distance in easel painting).

Ferrule: A metal (usually nickel- or brass-plated) sleeve that secures the brush hairs to the handle. It is crimped at both ends—around the handle and around the base of the bristles—to maintain stability and prevent shedding.

Flag: The natural split ends found at the tip of individual bristles—especially in hog hair brushes—that increase surface area, improve paint retention, and contribute to softer, more controlled mark-making.

Crimp: The indented or compressed section of the ferrule that holds it firmly to the handle.

Heel: The portion of the bristles that is inserted into the ferrule. It is often glued for added security.

Belly: The widest point of the bristle bundle. This area holds the bulk of the paint and influences the brush’s capacity for fluid delivery.

Toe: The very tip of the bristles—the part that touches the surface first. The shape of the toe can often define the brush type (e.g., round, flat, filbert, etc.).

Hair/Bristle Bundle: The working end of the brush composed of natural hair (e.g., sable, hog, mongoose) or synthetic fibers (e.g., nylon, taklon). Properties like spring, stiffness, and absorbency vary greatly depending on material.

The combination of these elements determines the brush’s performance in terms of flow control, mark precision, spring, and responsiveness. Artists often select brushes based on desired paint behavior, surface type, and working scale.”

Brush Deformation

“A general term describing any unwanted or unintended alteration in the shape, structure, or performance of a brush due to physical stress, improper maintenance, or prolonged use. Deformations can affect bristle alignment, paint delivery, edge control, and overall brush longevity. While some deformation may be gradual and expected with heavy use, others can result from avoidable handling errors. Common types include:

Splaying: The outward flaring or spreading of bristles, often caused by improper drying (e.g., storing the brush bristle-side down or letting moisture collect in the ferrule). Splaying disrupts edge control and creates unpredictable marks.

Curling: A deformation in which bristles begin to curve or twist, typically due to exposure to excessive heat, residual solvents, or prolonged pressure on a wet brush. More common in softer hairs or synthetics.

Flag Collapse: A condition in which the natural split tips (flags) of bristle brushes close or mat together, reducing paint retention and altering stroke texture. This may occur from insufficient cleaning, residue buildup, or prolonged submersion in solvent.

Ferrule Pinch Distortion: A crimping or warping of the ferrule that compresses the hair bundle unevenly, causing asymmetrical brush behavior. This can result from using tools to forcefully clean dried paint or from mechanical damage.

Root Swelling and Shedding: Caused by prolonged soaking or moisture retention at the base of the bristles, leading to fiber swelling, loosening, or complete detachment from the ferrule.

Preventing brush deformation involves proper cleaning, reshaping (e.g., brush tying), drying bristles downward or horizontally, avoiding prolonged solvent exposure, and storing brushes in a protective, upright or suspended position.”

Brush Dynamics

“Physical variables and motor strategies employed during the application of paint with a brush. These include motor-controlled factors—such as pressure, speed, stroke length, angle of contact, and directional change—as well as more specific manipulations like pivoting (a controlled rotation of the brush around a fixed point of contact to modulate stroke curvature, pressure distribution, or edge articulation) and twisting (rotation of the brush around its own longitudinal axis to reorient the brush tip). These are accompanied by material-interaction conditions (e.g., loading and unloading behavior, perceived resistance). All of these variables influence the appearance, texture, and structural behavior of the applied media.”

Unlike brushwork, which typically refers to the visible evidence of paint manipulation (e.g., stroke marks, layering, topography), brush dynamics describe the process by which those effects are achieved. This distinction allows for precise analysis and intentional modulation of effects such as edge quality, value transitions, and surface continuity.

Within the Waichulis Curriculum, brush dynamics are addressed in a manner similar to the drawing program’s approach to pressure modulation. Specific strategies (such as float (a low-pressure gliding motion that allows the brush to distribute or refine paint without fully engaging the bristle body; often used to maintain softness or delicacy in surface treatment), drag, compress, lift, or pivot) are employed to achieve desired outcomes in value control, form development, and edge calibration. Mastery of brush dynamics supports consistent media behavior across varied substrate conditions, tool types, and procedural phases.

Brush dynamics are essential for developing a predictable and controlled painting process, and should be trained with the same rigor and specificity as tonal pressure in drawing exercises.”

Brush Tying

“A maintenance technique used to preserve the shape and functionality of bristle brushes—particularly natural hog bristle—by wrapping the hair bundle in a controlled fashion after cleaning. Once washed and rinsed, a wetted string is gently wrapped around the ferrule and hair bundle to hold the bristles in a uniform shape as they dry. This wrapping should never be tight, as excessive pressure can cause the brush tip to flare outward, defeating the purpose of the procedure.

Brush tying helps prevent splaying, ensures the bristles dry into their intended shape, and significantly extends the lifespan of natural bristle brushes. It is especially important for brushes used in procedures that demand consistent edge control or specific shape retention. This technique is not typically applied to soft sables or synthetics, which are instead reshaped manually and dried upright in low-dust environments​.”

Brushwork

“The application and manipulation of paint via a brush, encompassing a range of dynamics influenced by brush type, media viscosity, surface texture, and motor strategies. Within the Waichulis Curriculum, brushwork is functionally categorized and optimized across three primary brush types—bristle, synthetic, and sable/synthetic sable blends—each deployed strategically to manage media characteristics and visual outcomes.

 Brushwork may also refer to the visible evidence of application dynamics, including paint topography, stroke direction, pressure traces, and layer thickness. These observable factors serve as indicators of procedural decisions, material behaviors, and the artist’s physical engagement with the surface.

In some art traditions, brushwork is more than procedural—it becomes a defining stylistic element. Artists such as Vincent Van Gogh, with his directional linear strokes, or Claude Monet, with his impasto dabs, leveraged brushwork as a visual signature, contributing both expressive and structural content. In these contexts, the texture and patterning of brush marks become an integral part of the pictorial message.

 However, in curriculum systems prioritizing representational accuracy (such as Waichulis), brushwork is calibrated to reduce unwanted artifacting and enhance perceptual clarity—serving more as a tool for control than for expression. Terms like ‘energy transfer in brushwork’ are regarded metaphorically, describing the physical consequences of stroke dynamics, rather than any literal force transference.”

Buffer Color

“A deliberately placed intermediary color that serves to moderate, delay, or redirect chromatic interaction between two adjacent or overlapping passages—particularly in complex transitions or multi-pass painting workflows. Unlike a chromophage, which is typically a direct corrective response to an unwanted color artifact within a live (active) gradation, a buffer color may be introduced proactively or indirectly to shape how subsequent applications will visually and materially interact.

Buffer colors often function by neutralizing or softening transitions between dissimilar hues to prevent jarring chromatic shifts, temporarily occupying a space to be layered upon in future sessions, influencing subsequent optical mixture or glaze behavior, or preventing pigment contamination or bleeding when working wet-in-wet or during staged indirect painting techniques

For example, when transitioning from a cool green shadow to a warm flesh tone, an intermediary neutral or desaturated buffer color may be applied first to bridge the temperature and chroma disparity, thus preserving cohesion and avoiding direct discord. This concept is especially relevant in indirect painting or multi-stage arrival strategies, where the final perceptual outcome is the result of several layered interactions, and early decisions must anticipate future material behaviors. In this way, buffer colors are not reactive like chromophages, but strategic placeholders or mediators—used to optimize compositional flow, spatial development, and chromatic control over time.”

Burin

“A steel engraving tool with a sharp, oblique point, used to incise designs into metal plates for printmaking. Mastery of the burin is essential for artists specializing in engraving, as it requires precision and control to create detailed images.”

Burnish (Drawing Surface)

“The compression or polishing of a drawing surface, typically caused by excessive or repeated pressure from a drawing tool, blending instrument, or eraser. This physical alteration flattens the tooth (surface texture) of the paper, reducing its ability to accept additional material. As a result, subsequent applications of charcoal, graphite, or pastel may appear lighter, resist adhesion, or exhibit uneven buildup.

In the Waichulis Curriculum, burnishing is considered a surface compromise—particularly in pressure scale and gradation exercises—where control over value and material layering is essential. Burnishing can lead to inconsistent value transitions, visible textural shifts, or ‘slick spots’ that resist correction. To avoid burnishing, students are encouraged to use light, controlled pressure, and to work gradually when building value, preserving the paper’s receptive quality throughout the drawing process.”

Bust

“A sculptural representation of a person’s head, shoulders, and upper chest.”