Dada

“(Also known as Dadaism) An early 20th-century avant-garde art movement that emerged in response to the horrors of World War I and the perceived absurdities of modern society, nationalism, and traditional cultural values. Originating in Zurich, Switzerland, in 1916 at the Cabaret Voltaire, Dada quickly spread to major cities like Berlin, Paris, and New York, becoming a transnational, anti-art phenomenon.

Dada was not a style, but an attitude—marked by the rejection of reason, logic, and aesthetic convention, an embrace of nonsense, irrationality, spontaneity, and disruption, the use of readymades (ordinary objects designated as art, e.g., Duchamp’s Fountain), and collage, photomontage, assemblage, performance, and chance operations.

Artists such as Marcel Duchamp, Hannah Höch, Tristan Tzara, Jean Arp, and Man Ray used their work to undermine traditional definitions of art, question authorship and originality, and challenge institutional authority. Dada was not meant to be beautiful or coherent—it was meant to provoke, destabilize, and reflect the chaos of a world that had made war mechanized and ideology lethal.

The name Dada itself is intentionally absurd—it may refer to the French word for ‘hobby horse‘ or simply have been chosen at random from a dictionary. This arbitrariness was emblematic of the movement’s rejection of rational systems.

Though relatively short-lived (roughly 1916–1924), Dada had a profound impact on the development of modern and contemporary art: It laid the groundwork for Surrealism, Conceptual Art, Fluxus, and aspects of Postmodernism. It introduced the idea that the concept or context of a work could be more important than its formal execution. It radically expanded what could be considered ‘art,’ helping to unseat long-standing hierarchies of medium, skill, and intent.

Ultimately, Dada was not simply an art movement—it was a cultural rebellion against the logic of systems that led to destruction, and a bold experiment in redefining the boundaries of artistic expression.”

Damar

“A natural resin obtained from trees in the Dipterocarpaceae family, primarily harvested in Southeast Asia. Damar appears as brittle, translucent lumps and is dissolved in turpentine to create damar varnish, used in oil painting as a final or retouching varnish.

Damar produces a harder, less yellowing, and more moisture-resistant coating than mastic, making it a preferred traditional varnish for many painters and restorers throughout the 20th century. It dries with a smooth finish and has good optical clarity but still suffers from some long-term degradation (e.g., yellowing, embrittlement), leading modern conservators to often favor synthetic options. Damar came into widespread use in the late 19th century, largely replacing mastic in many varnish applications due to its superior working properties and improved resistance to environmental damage. Its name is derived from the Malay word for resin, and its rise paralleled expanded European access to Southeast Asian trade routes.”

Dead Color Stage (Dodecimo, Underpainting Layer, Dead Coloring)

“An early underpainting phase in traditional oil painting, particularly associated with Flemish, Venetian, and Dutch painting techniques of the Renaissance and Baroque periods. It involves the first full pass of opaque local colors applied to contribute to developing values structures, volumes, and compositional relationships before subsequent layers of glazing, detailing, and final modeling.”

Decorative Arts

“A broad category of applied visual arts concerned with the design and embellishment of functional objects. This includes works in media such as ceramics, glass, metalwork, textiles, furniture, and jewelry, where both aesthetic form and utility are integral to the object’s creation. Unlike the fine arts—traditionally associated with painting, sculpture, and architecture—the decorative arts are defined by their integration of ornament and function, often serving daily, ritual, or domestic purposes while embodying cultural values, craftsmanship, and visual expression.

Historically, the decorative arts have been essential components of artistic production across nearly all cultures, with some of the earliest known examples including Neolithic pottery, woven textiles, and ritual objects that reflect symbolic, religious, or social significance. During the Renaissance and Baroque periods, decorative arts flourished in European courts and guilds, with artisans specializing in highly refined inlay, enameling, and textile production. In the Arts and Crafts Movement (late 19th century), figures like William Morris elevated the decorative arts as a response to industrial mass production, emphasizing the unity of design, material honesty, and craftsmanship.

While historically marginalized in Western art hierarchies (particularly during the rise of modernist distinctions between ‘high’ and ‘low’ art), the decorative arts have long been recognized in non-Western traditions as equally expressive and culturally central. Modern scholarship increasingly views the decorative arts not as subordinate to fine art but as parallel modes of aesthetic communication, combining technical expertise, pattern logic, material innovation, and symbolic design.

In museum and academic contexts, the term is often used to distinguish such objects from pure utilitarian tools or conceptual fine art, although that boundary is increasingly blurred by contemporary practice. Today, the decorative arts are studied not only for their visual and technical sophistication, but also for what they reveal about cultural identity, trade networks, domestic life, and symbolic language across civilizations.”

Definition (Visual Information)

“In the context of visual information, definition refers to the perceptual clarity and distinctness of visual elements, particularly the degree to which edges, forms, values, or textures are resolved and differentiated within a given field of view. High-definition implies a high density of perceptually salient information, supported by strong local contrast, edge acuity, focused attention, and spatial frequency resolution. This perceptual clarity facilitates efficient recognition and interpretation by the observer.

While the term ‘definition’ is often associated with photographic or digital resolution, in perceptual terms it more accurately reflects how richly structured and fluently interpreted visual information is. This aligns with the Waichulis Curriculum’s emphasis on the deliberate modulation of visual phenomena—such as edge behavior, contrast gradients, and shape boundaries—as part of a structured visual language designed to guide attention, establish spatial hierarchies, and support narrative intent.”

Defocus Blur

“A visual effect where an image appears out of focus due to light from an object being distributed over a larger area on the retina or camera sensor, rather than forming a sharp point. This occurs when the eye’s lens or a camera lens fails to precisely converge light rays onto the focal plane. In human vision, defocus blur serves as a monocular depth cue, contributing to depth perception by simulating the way objects appear progressively more blurred as they move out of focus. This effect is used in photography and cinematography to create a sense of depth and emphasis on focal points​.”

Delamination

“The physical separation or failure of adhesion between discrete layers within a painting or drawing structure—such as between the support and ground, ground and paint, or between individual paint layers. This condition compromises the structural integrity of the artwork and can lead to lifting, flaking, or loss of surface material over time.

In the context of traditional oil painting, as detailed in Ralph Mayer’s The Artist’s Handbook, a painting is considered a laminated structure: composed of support, ground, and successive layers of color. These layers must be built according to specific physical and chemical principles to maintain cohesion. Delamination most often occurs when: a less flexible layer is applied over a more elastic one (violating the ‘fat over lean’ principle), the binding power of a new layer is weaker than that of the underlying one, improperly prepared or overly absorbent grounds are used, or environmental stress (e.g., humidity or temperature fluctuations) causes differential expansion and contraction between layers​.

A common example includes oil paint delaminating from an acrylic or overly glossy surface, or ground layers separating from poorly sealed canvas. Mayer emphasizes that stable lamination depends on textural compatibility, mechanical tooth, and relative flexibility. Preventative strategies include: proper surface preparation (e.g., well-sealed, appropriately absorbent grounds), following material compatibility guidelines (e.g., no brittle layers over elastic ones), and avoiding contamination from oils, soaps, or environmental agents.

Delamination is not just a cosmetic issue—it is a sign of mechanical instability and can lead to irreversible loss if not addressed through conservation measures.”

Deliberate Practice

“A highly structured, effortful form of training that targets specific aspects of performance for improvement through repetition, feedback, and cognitive engagement. It differs fundamentally from passive repetition or routine execution in that each practice session is explicitly designed to stretch the learner’s current ability, reinforce accurate procedural memory, and incrementally refine performance.

Within the Waichulis Curriculum, deliberate practice is the cornerstone of skill development, underpinning every stage from early perceptual calibration to creative fluency. It is implemented through sequential, progressively calibrated exercises that challenge learners to operate at the edge of their current proficiency while avoiding overwhelming complexity.

The curriculum defines four essential components of deliberate practice:

Motivation and Effort towards a Clearly Defined Goal
The learner must be genuinely motivated and willing to exert focused, sustained effort. Since deliberate practice often pushes the learner beyond comfortable performance zones, sustained motivation is required to tolerate challenge, persist through failure, and refine skills over time.

Building on Prior Knowledge
Tasks are constructed with respect to the learner’s existing competencies, ensuring that each new challenge can be understood and acted upon with minimal initial instruction. This scaffolding respects cognitive load limitations and supports progressive integration of new skills.

Immediate and Informative Feedback
Feedback must be timely, specific, and actionable—whether external (from an instructor or structured rubric) or internal (from calibrated perceptual comparison). Without rapid feedback loops, errors may become habitual and more difficult to correct later.

Repetition and Refinement
Targeted tasks are repeated across many iterations, with each repetition offering an opportunity to refine performance. Repetition in this context is not mechanical, but adaptive—requiring constant micro-adjustments and strategic attention to improve fidelity and control.

Deliberate practice in the Waichulis system emphasizes the quality and structure of repetition, not just time spent. It is the mechanism by which procedural fluency, automaticity, and expert-level precision are developed and maintained. Without it, learners risk stagnating at habitual levels of performance rather than progressing toward adaptive expertise.”

Denglas

“A high-quality, low-reflective, UV-filtering picture framing glass designed to minimize glare and protect works of art from environmental damage. It is commonly used in museums, galleries, and professional framing applications where preservation and visibility are both prioritized. Denglas typically refers to a brand or type of conservation glass that incorporates multiple features: anti-reflective coatings, ultraviolet light filtration (often up to 99% of UV), and optical clarity that ensures minimal visual interference with the artwork.

Unlike standard framing glass, which can produce distracting glare and may transmit UV radiation that degrades pigments and paper over time, Denglas offers a nearly invisible surface under normal viewing conditions. This property enhances the perceptual experience of the work without sacrificing protection.

The use of specialized conservation glazing materials emerged alongside increased awareness of light-induced deterioration in works on paper, textiles, and photographic media. Conservation-grade glazing became standard in institutional settings during the late 20th century, especially after research highlighted the effects of UV exposure on organic materials. Denglas was among the first products to offer a combination of anti-reflective and UV-protective properties in a single sheet, leading to widespread adoption in museum-grade framing.

Today, Denglas is considered one of several industry-standard options alongside products like Museum Glass®, Optium Museum Acrylic®, and Tru Vue®. It is particularly favored when the aesthetic goal is to make the glazing as ‘invisible’ as possible to the viewer, while ensuring conservation safety for high-value or light-sensitive works.

Note: The term ‘Denglas’ may sometimes be used generically in art and framing communities to refer to any similar high-performance conservation glass, although it originally denoted a specific brand or manufacturer.”

Depth of Field (DOF)

“The range of distances within a scene that appears acceptably sharp in an image or visual perception. It is influenced by aperture size, focal length, sensor size, and viewing distance. A shallow depth of field results in a blurred background and foreground, while a deep depth of field keeps most of the scene in focus. In human vision, depth of field is dynamically adjusted by the eye’s pupil size and lens accommodation, allowing us to focus on objects at different distances while the surroundings blur. This is a key factor in depth perception and selective attention​.”

Design

“In the context of visual art and the Waichulis Curriculum, refers to the deliberate arrangement and manipulation of visual elements (e.g., line, shape, value, color, texture, space, form, depth) according to design principles (e.g., balance, contrast, emphasis, movement, visual rhythm, unity) to achieve effective visual communication and aesthetic impact.

Design is not synonymous with decoration or arbitrary rule-following. Instead, it is the product of purposeful structuring that maximizes communication efficacy—how clearly an image conveys meaning—and aesthetic quality—how well it engages biological preferences and perceptual tendencies. Waichulis emphasizes that design, particularly in pictorial composition, is not about applying rote formulas but about strategically managing information in a way that aligns with how human vision processes and prioritizes visual input​.”

Diagnostic Wheel

“A self-assessment and calibration tool used within the Waichulis Curriculum to enhance perceptual-motor control and spatial adaptability during the Origin-Destination Line Exercise. It is designed to help learners evaluate their directional consistency and line quality across multiple vector orientations.

Constructed by drawing a large circle using a compass, the wheel designates a central origin point and a series of evenly spaced destination dots placed along the perimeter. The learner’s task is to draw straight, deliberate lines from the origin to each destination dot, maintaining the same level of pressure control, line accuracy, and fluidity as developed in prior Origin-Destination exercises.

This exercise is not merely a test of technical control, but a diagnostic tool for directional performance analysis. By examining the results, students can detect: wobbling or deviation in certain directions, pressure inconsistencies across vectors, and systematic directional weaknesses in motor execution.

The Diagnostic Wheel enables students to identify specific problem orientations—those angles or directions in which line control falters—and then prioritize those directions for targeted practice in subsequent exercises​.

As a feedback loop embedded in deliberate practice, the Diagnostic Wheel reinforces adaptive mark-making and supports the development of directional fluency, both of which are essential for complex shape construction and gestural control in later representational tasks.”

Diffuse Surface Reflectance

“The behavior of light as it interacts with a surface composed of numerous microscopically varied planes, causing aggregate reflected light to be scattered across many directions. While each individual ray of light continues to obey the law of reflection at the local level (angle of incidence equals angle of reflection), the highly irregular surface geometry results in an aggregate reflection pattern that appears evenly distributed to the observer. This behavior contrasts with specular reflection, where light reflects uniformly from smooth surfaces in a singular, predictable direction. The visual result of diffuse reflectance is that the brightness of the surface remains relatively consistent regardless of the observer’s viewing angle—a property that is crucial for form modeling in perceptual drawing and painting. This phenomenon is well-approximated by Lambertian reflection, which assumes that the intensity of reflected light falls off with the cosine of the angle to the viewer. In the Waichulis Curriculum, learners work extensively with materials and surfaces that exhibit diffuse reflectance (e.g., charcoal on paper), allowing value relationships to be modeled without directional glare or shifting highlights, and supporting more stable perceptual cues for surface orientation and mass.”

Diffusion

“The physical scattering of light as it passes through a medium or interacts with irregular particles or surfaces. In a visual arts context, diffusion plays a critical role in how light behavior softens shadows, blurs edges, and contributes to ambient illumination. This phenomenon occurs in environments where light rays are redirected in multiple directions, often due to suspended particles (as in fog or smoke), translucent materials (like skin or frosted glass), or semi-permeable barriers. The presence of diffusion can significantly alter the appearance of cast shadows, edge transitions, and form visibility—especially under indirect lighting conditions. Artists must understand diffusion to anticipate and replicate soft gradations and atmospheric effects with accuracy. For example, a form illuminated through a diffuse medium will show gentler value transitions and diminished edge acuity, requiring careful modulation to preserve dimensional integrity. In the Waichulis Curriculum, an understanding of diffusion is implicit in the study of form modeling and environmental lighting, where learners learn to identify and replicate conditions that result in softened perceptual boundaries or desaturated light behaviors.”

Diluent

“A liquid added to a paint, ink, or medium to reduce its viscosity—that is, to make it thinner and easier to apply—without fundamentally altering its chemical composition. In painting, diluents are often volatile solvents like turpentine or mineral spirits, which evaporate after application, leaving behind only the pigment and binder. Unlike mediums (which modify drying time, gloss, or film strength), diluents are typically used for mechanical adjustment—to control how fluid or spreadable a substance is during application.

In painting, a diluent is often a solvent used in a specific way—but the two terms are not interchangeable. A diluent is defined by its function: to thin a substance and reduce its viscosity through physical dispersion, not chemical breakdown. A solvent, by contrast, is defined by its capacity to dissolve other materials at the molecular level. For example, turpentine acts as a diluent when used to thin oil paint, spreading out the binder and pigment particles without altering them chemically. The same turpentine functions as a solvent when it is used to dissolve damar resin or to clean dried paint from brushes. In short, dissolving involves a chemical interaction that creates a true solution, while diluting involves physically spreading components to alter consistency. The distinction between the two lies not in the substance itself, but in how it is used.”

Diluting

“A physical dispersion, where the added liquid spreads out the binder/pigment particles, lowering viscosity, but not chemically altering or breaking them down.”

Directional Emphasis in Drawing

“The use of lines, shapes, or shading to suggest a directional flow within a composition, often intended to reinforce narrative elements or focal points. While this strategy is commonly employed to guide a viewer’s gaze, Yarbus’ research on eye movement demonstrates that gaze paths are influenced more by the viewer’s intent and the specific problem they are trying to solve rather than by explicit visual cues alone. As a result, while directional emphasis can encourage certain perceptual tendencies, it cannot reliably dictate a viewer’s eye movement.”

Disparity

“In its most general sense, disparity refers to a difference or lack of correspondence between two or more elements. In the context of visual perception, disparity is a critical term used to describe the positional difference of an object’s image as seen by the left and right eyes. This positional mismatch—known as binocular disparity—is a fundamental cue for stereoscopic depth perception. Because the eyes are horizontally separated (typically by about 6.5 cm in humans), each eye captures a slightly different image of the world. The brain uses these differences to triangulate distance and perceive three-dimensional structure in space.

Binocular disparity is greatest for objects that are closer to the viewer and decreases with distance. When the brain fuses these two slightly offset retinal images into a single percept, the disparity information is processed to generate a sense of depth, volume, and spatial relationship. This mechanism underlies stereopsis, the ability to perceive depth based purely on the comparison of two monocular images.

In representational art training, understanding disparity can inform pictorial depth cues, spatial compression, and overlap strategies, even though the artwork itself is presented on a flat, monocular surface. Additionally, disparities between elements—whether in scale, orientation, or value—can also serve as design tools to create visual tension, hierarchical contrast, or narrative separation within a composition.”

Dissolving

“A chemical interaction where one substance (solute) breaks down at the molecular level into another (solvent), forming a true solution.”

Distal Stimulus

“The actual object or event in the environment that gives rise to sensory input. It exists independently of the observer and serves as the source of the proximal stimulus. Distinguishing between proximal and distal stimuli highlights the interpretive challenge of perception: the brain must infer external reality from incomplete sensory input.”

Distortion

“In visual representation and optics, distortion refers to any alteration of an object’s perceived or depicted shape, proportions, or spatial relationships relative to a normative or expected configuration. It may occur due to lens aberrations (e.g., barrel or pincushion distortion), perspective exaggerations, or deliberate artistic stylization. In perceptual science, distortion may arise from limitations or biases in the visual system, such as size or shape constancy failures.”

Distributed Emphasis

“A compositional strategy in which visual interest is intentionally spread across multiple elements or regions, rather than concentrated in a single dominant focal point or area. This approach results in a more uniform or non-hierarchical visual field (sometimes referred to metaphorically as ‘egalitarian visual field’ (a pictorial environment in which no single element is granted overwhelming perceptual dominance)), encouraging the viewer to explore the image more freely rather than being drawn immediately to a hierarchical center of attention.

Distributed emphasis may be achieved through the repetition of similarly weighted elements, uniform treatment of detail or contrast, avoidance of directional cues, or structural balance across the pictorial space. Rather than privileging one area as ‘more important,’ this strategy allows for multiple micro-foci or a continuously engaging surface, often inviting longer or more open-ended viewing experiences.

This approach contrasts with traditional focal structures—such as dominant focal points or areas of strong visual hierarchy—which are designed to influence a viewer’s attention in a specific sequence. Distributed emphasis, by comparison, may discourage linear scanning and instead promote a relational or ambient mode of engagement, where attention flows more organically.

Distributed emphasis is frequently found in: all-over compositions (e.g., Abstract Expressionism, certain textile designs), decorative pattern systems, narrative works with multiple vignettes or subject groupings, and image-making practices that intentionally reject singularity or hierarchy as compositional ideals.

When employed skillfully, distributed emphasis can create a sense of compositional unity without dominance, supporting visual complexity while resisting forced prioritization. However, it demands careful management of visual balance, rhythm, and relational contrast to prevent perceptual flatness or viewer fatigue.”

Divider

“A handheld measuring instrument composed of two pointed metal legs joined by a hinge or tension joint, traditionally used to measure, transfer, or subdivide fixed intervals. In visual art training, particularly within the Waichulis Curriculum, dividers are functionally interchangeable with calipers and are employed to support comparative measurement, proportional layout, and spatial calibration.

While both tools share structural and functional similarities, dividers are typically distinguished by their sharp, needle-like points and are often favored for stepping-off consistent measurements along a surface (e.g., marking equal divisions along a contour or axis). In contrast, calipers may feature more rounded or adjustable tips suited for measuring across surfaces or volumes.

Despite this traditional distinction, the Waichulis Curriculum treats the use of calipers and dividers as pedagogically equivalent: both serve as external reference tools that help learners gauge proportional relationships and spatial intervals during exercises such as shape replication, form builds, and sight-size transfers. However, they are not intended to replace perceptual judgment, but to support the development of cultivated perception and action associations—reinforcing consistent alignment and comparative accuracy during early perceptual training.

Ultimately, whether referred to as calipers or dividers, the tool’s role remains the same: to provide a reliable physical benchmark that enhances the learner’s ability to assess spatial relationships with growing independence and precision.”

Divisionism

“A 19th-century painting technique and color theory approach in which color is separated into individual components and applied in discrete, often small strokes or dots, allowing the viewer’s eye to perform the optical mixing of hues at a perceptual—not physical—level. It is closely associated with the broader Neo-Impressionist movement and is sometimes used interchangeably with Pointillism—though important distinctions exist.

The term was formalized in the writings of Paul Signac, who, along with Georges Seurat, pioneered this approach following the influence of contemporary color theories from scientists like Michel Eugène Chevreul and Ogden Rood. Where traditional methods physically mixed pigments on the palette or canvas, Divisionism aimed to preserve the luminosity and saturation of pure colors by placing them adjacently rather than blending them.

In practice, Divisionism is defined by the strategic separation of complementary and analogous hues—often as small, regular marks or strokes. This compositional method rests on the principle of optical mixing, where spatial proximity and retinal integration combine the perceived components into a cohesive image. This method not only enhanced chromatic intensity but also produced a dynamic visual vibration, exploiting the human visual system’s limitations in resolving fine detail from a distance.

From a vision science perspective, Divisionism draws directly on spatial frequency integration, where the visual system’s lower-resolution peripheral processing averages fine chromatic detail across receptive fields. As Stephen E. Palmer outlines in Vision Science: Photons to Phenomenology, perceptual integration of fragmented stimuli is mediated by both bottom-up channel summation and top-down expectations, both of which are leveraged in Divisionist compositions.

Importantly, Divisionism is not synonymous with Pointillism. While Pointillism emphasizes a uniform application of dot-like marks, Divisionism refers more broadly to the conceptual separation of color and its perceptual reassembly. For example, Signac’s brushwork may include linear strokes or patch-like tessellations, not just dots—making the term more about principle than mechanics.

In training contexts, Divisionism can serves as a case study in perceptual mechanics and color interaction—highlighting how chromatic juxtaposition, spatial resolution, and observer distance influence visual experience. Understanding this method supports insights into edge behavior, simultaneous contrast, and compositional tension—all of which inform strategies for color stacking, atmosphere construction, and visual hierarchy in representational painting.”

Dogma

“A set of principles or beliefs (often treated as universal truths without validation) that are accepted by a group or institution as incontrovertibly true, often without empirical evidence or critical scrutiny. In the context of perceptual science, artistic training, or theoretical discourse, dogma is typically seen as a hindrance to progress. It reflects rigid adherence to tradition or authority over evidence-based inquiry and open theoretical integration. Avoiding dogma allows for interdisciplinary collaboration and the evolution of more comprehensive models of understanding—especially in fields where competing theories (e.g., structuralism, Gestaltism, ecological optics, constructivism) must be reconciled through empirical reasoning rather than ideological allegiance​.”

Dominance (Visual)

“The condition in which one or more elements within a composition exert a stronger perceptual pull than surrounding elements, making them more likely to attract or hold the viewer’s attention. Dominance is a function of visual salience, which arises from perceptual contrasts—such as differences in value, color, edge resolution, size, shape, orientation, or texture—as well as compositional placement and contextual relationships.

Dominance plays a key role in establishing visual hierarchy, helping the viewer prioritize information and navigate the image. Dominant elements tend to emerge as figure against ground, often guiding perception toward focal points or areas of narrative significance. However, unlike a focal point (which is typically discrete and deliberate), visual dominance may be distributed across multiple zones or emerge organically from perceptual conditions.

Empirically, dominance is supported by models of attentional salience and feature contrast in vision science. For example, high-contrast elements or those with unique feature values relative to their neighbors are more likely to trigger fixations or interrupt visual scanning. Artists may intentionally modulate dominance to orchestrate movement, create balance, or destabilize expectations within a composition.

Importantly, dominance is context-sensitive: an element that is dominant in one composition may be recessive in another, depending on its perceptual relationship to surrounding content. Effective control of dominance requires understanding not just what an element is, but how it differs from what surrounds it.”

Dot

“A mark that indicates a point in space.”

Double Primary Palette

“A color palette configuration that includes, but is not limited to, two different pigments for each of the three historical primary colors—red, yellow, and blue. Typically, one of each pair leans toward a warmer bias (closer to orange, green, or violet), while the other leans cooler. This configuration enables artists to mix a broader and more chromatically accurate range of hues across the color spectrum. Within the Waichulis curriculum, the standard double primary palette consists of: Yellows: Naples Yellow and Cadmium Yellow Light, Reds: Cadmium Red Light and Alizarin Crimson, and Blues: Ultramarine Blue and Phthalo Blue.

This arrangement, complemented by Titanium White, Permanent Green Light, Lamp Black, and 2–3 neutral earth tones, allows for a wide gamut and nuanced color mixing. The palette is explored systematically in the Basic Palette Color Chart, which demonstrates how mixing each color with its neighbors reveals interaction dynamics and mixing potential​.”

Drafting / Draftsmanship

“The technical, perceptual, and cognitive proficiency involved in executing controlled and deliberate drawings. In the Waichulis Curriculum, it encompasses accurate observation, confident line-making, and the effective simplification of complex visual input through perceptual chunking and structural translation.

Deliberate draftsmanship is most evident in the confident line—a purposeful, unhesitant mark that reflects both motor control and cognitive intention. Such lines serve as indicators of both observational clarity and procedural fluency. Through early training exercises like Origin-Destination Lines, Shape Replication, and Form Construction, students develop the motor precision, pressure sensitivity, and spatial reasoning that underpin high-level drawing performance. These core competencies culminate in advanced integration challenges such as The Gauntlet—a capstone designed to measure the student’s fluency in all major drafting domains.

Historically, draftsmanship has held a privileged position in the academic art traditions of the West, particularly within the ateliers and academies of Europe. Mastery of drawing was often seen as a prerequisite for painting and sculpture, with institutions like the École des Beaux-Arts in Paris emphasizing it as the foundation of visual literacy. The term also evokes an era in which the ability to draw with precision was equated with intellectual rigor and artistic legitimacy. However, while historical notions of draftsmanship often emphasized anatomical accuracy and idealized proportion, the Waichulis approach aligns more with contemporary perceptual science—prioritizing the accurate mediation of sensory input through deliberate, context-sensitive strategies rather than adherence to formulaic ideals.

Thus, within the Waichulis system, draftsmanship is not an aesthetic ideal but a procedural competency—one that enables artists to translate the dynamic complexity of the visual world into intelligible pictorial form with empirical consistency.”

Drawing

“The act of mark-making that uses lines, shapes, and tonal modulation to represent, suggest, or conceptualize objects, forms, ideas, or symbolic systems on a surface. It is one of the most fundamental and ancient forms of human visual expression—both a process of cognition and a product of communication. At its core, drawing involves the deliberate deposition of material (e.g., charcoal, ochre, ink) onto a contrasting substrate, creating visual structures that may correspond to external references, internal concepts, or abstract formal relationships. In representational contexts, drawing serves as a means to translate perceptual input (or mental imagery) into a two-dimensional surrogate, often requiring the integration of measurement, memory, and calibration. In non-representational or symbolic contexts, drawing can serve ritual, linguistic, notational, or exploratory purposes.

The earliest known examples of drawing predate written language and have been discovered in archaeological contexts dating back at least 73,000 years, such as the engraved crosshatched ochre pattern found in Blombos Cave, South Africa. These prehistoric marks indicate intentional visual structuring, and likely served communicative, symbolic, or mnemonic functions. Other Paleolithic cave sites—such as Chauvet-Pont-d’Arc in France (ca. 30,000–32,000 BCE)—show highly developed representational drawings of animals rendered with charcoal, ochre, and engraved lines, demonstrating not only technical sophistication but also an acute observational understanding of animal behavior and form. These early drawings are believed to reflect social, ritual, and mnemonic practices, supporting the idea that drawing evolved as a tool for externalizing internal knowledge and enhancing group-level communication.

In formal artistic training, drawing is both an independent discipline and a foundational skill for all representational practices. It provides a direct platform for developing perceptual fluency, structural logic, and the capacity to encode depth, light, form, and texture on a flat surface. Whether executed with dry media (e.g., graphite, charcoal, conté) or wet media (e.g., ink or wash), drawing emphasizes line, edge, proportion, and value, making it uniquely suited for skill-building in controlled environments. Contemporary cognitive science also identifies drawing as an embodied cognitive activity—integrating motor control, spatial reasoning, and symbolic encoding—serving both expressive and analytic functions.

In summary, drawing is a multifunctional visual language rooted in the earliest material traces of human cognition. It remains central to human creativity, perception, communication, and cultural memory across time and disciplines.”

Drawing Board

“A flat, rigid support surface used to secure a drawing substrate during execution. Typically constructed from wood, masonite, or high-density fiberboard, drawing boards provide the structural stability necessary for precision-based mark-making. Within the Waichulis Curriculum, the drawing board serves as a foundational tool in perceptual training, often paired with an easel to position the surface at an angle closer to vertical. This orientation helps mitigate perspective distortion, ergonomic strain, and control issues associated with working on a flat horizontal surface​.

While the board itself does not directly affect material adhesion, its hardness and stability can influence the transmission of pressure during mark-making. For this reason, practitioners often place a clean stack of paper beneath the active drawing sheet to soften the interface between the rigid support and the drawing tool—helping to preserve the paper’s tooth and minimize compression artifacts. Additionally, if the board has a damaged or uneven surface, it may introduce unintended texture or distortions into the drawing, particularly in pressure-sensitive applications.

Drawing boards are also commonly used to clip or tape down papers and reference materials, enabling consistent subject-to-surface alignment critical for sight-size and comparative methods. In instructional and studio contexts, they support the reliable deployment of shape replication tasks, pressure scales, and early form development exercises, providing an essential platform for foundational mark and material control.”

Drawing from Life (Working from Life)

“The practice of creating works based on direct observation of three-dimensional subjects in real space—such as human models, still life arrangements, architectural elements, or natural forms—as opposed to using flat, two-dimensional references. This process engages the artist in interpreting complex spatial relationships, lighting conditions, foreshortening, and perceptual variances in real time. Drawing from life presents unique challenges, including parallax distortion, variable light and viewpoint, and the need to continuously reassess proportions and orientation from a fixed vantage point. Within structured representational curricula like the Waichulis Program, drawing from life builds on earlier skill development from flat references and requires refined, adaptable spatial reasoning to achieve accurate and convincing form translations.

Historically, drawing from life represented an advanced stage of academic art training, following initial work copying flat plates and plaster casts. At institutions such as the École des Beaux-Arts, students progressed to the life room (atelier de dessin d’après nature) where they would render clothed or nude models under controlled lighting conditions. This stage was considered a culminating test of observational ability and draftsmanship, reflecting an artist’s readiness for compositional invention and painting. In modern perceptual training, drawing from life remains central to understanding form, light behavior, and spatial context, providing perceptual feedback not available in flattened photographic references.”

Drawing from the Flat

“The practice of creating drawings based on two-dimensional references, such as photographs, prints, engravings, or other pre-existing images, rather than from direct observation of three-dimensional subjects (drawing from life). This exercise is designed to develop key foundational skills, including shape accuracy, proportional reasoning, edge control, and value translation, by focusing on the replication of visual information from one flat plane to another. In the Waichulis Curriculum, this process is taught using structured methods such as sight-size, comparative measurement, and grid transfer, which facilitate accurate scaling, alignment, and spatial calibration.

Historically, drawing from the flat was a core component of 18th- and 19th-century academic art training, particularly in institutions such as the École des Beaux-Arts in France. Students would begin their formal training by copying from flat masterworks or standardized lithographs (often referred to as académies or planches), including prints of classical sculptures and anatomical studies. These plates served as controlled visual references, allowing students to refine their technique without the added complexity of translating from three-dimensional observation. This phase preceded drawing from plaster casts and eventually live models, forming a systematic, hierarchical progression from flat replication to fully spatial interpretation.

While the perceptual demands of drawing from the flat differ from those of drawing from life—due to the absence of real-world depth, parallax, and shifting lighting—this exercise remains a powerful tool for building visual calibration, motor control, and compositional judgment in representational training programs.”

Dry-Brush

“A method of paint application using a lightly loaded brush—often with minimal or no medium—across a dry substrate, allowing the bristles to skip across surface texture and deposit fragmented or broken patterns of paint. The result is a controlled distribution of pigment that preserves surface texture and enables fine detail work, optical blending, and subtle modulation without wet-in-wet diffusion.

An important distinction to note is that while scumbling may incorporate dry-brush mechanics, dry-brush is a more general application strategy involving the amount or quality of paint on a brush, not necessarily aimed at tonal or chromatic veiling. Scumbling specifically involves modifying an underlayer with a semi-opaque veil, while dry-brush may serve structural, textural, or refinement functions without altering underlying hue or value.

In the Waichulis Curriculum, dry-brush is introduced only after students achieve reliable control over brush pressure, directionality, and paint load. It is used to enhance surface complexity, introduce tactile cues, or refine edges and transitions without resorting to soft blending or excessive layering.”

Drying

“In the context of art materials, drying refers specifically to the physical process by which a liquid medium transitions into a solid or semi-solid state through the evaporation of volatile components (i.e., substances that evaporate readily at room temperature)—typically water or solvents. This process is governed by environmental factors such as temperature, humidity, air circulation, and the surface area of the exposed film. Drying by evaporation should be distinguished from chemical curing processes, such as the oxidative polymerization of drying oils, which are often colloquially referred to as ‘drying’ but are fundamentally distinct in mechanism. In the Waichulis Curriculum, understanding this distinction is critical for material control: media that dry through evaporation can often be reactivated or manipulated with additional solvent or moisture, whereas those that cure through chemical reaction typically become increasingly resistant to modification over time. Drying time directly impacts workflow, layering strategies, and the temporal behavior of visual phenomena such as edge softness, blending capacity, and pigment settling.”

Drying Oil

“A type of vegetable oil that forms a solid, durable film through oxidation rather than evaporation. These oils consist primarily of triglycerides—esters formed from glycerin and unsaturated fatty acids, particularly linoleic and linolenic acids—which readily react with oxygen from the air. During this oxidative polymerization process, the oil absorbs oxygen, undergoes complex molecular cross-linking, and transitions from a liquid to a solid state, forming the tough, insoluble substance known as linoxyn. This film cannot be redissolved into the original oil state, distinguishing drying from mere hardening through solvent loss. Common drying oils used in painting include linseed oil, walnut oil, poppyseed oil, and safflower oil, each varying in drying rate, film strength, and yellowing tendency depending on their fatty acid composition. For example, linseed oil dries quickly and forms a strong film but is more prone to yellowing, whereas poppy oil yellows less but dries more slowly and forms a weaker film​. The proper function of a drying oil in painting includes acting as a vehicle for pigment dispersion, a binder to form a cohesive film, an adhesive to anchor pigment to the substrate, and an optical modifier to enhance color depth and transparency​. Environmental conditions such as humidity, light exposure, and temperature, as well as oil processing methods (e.g., cold-pressed vs. boiled), significantly affect drying performance and film stability.”

Drying Time

“The duration required for a paint, ground, or other art material to become sufficiently set or cured to allow for continued work or overpainting without compromising surface integrity. However, the term ‘drying’ can be misleading, as the mechanism varies by medium:

In water-based media (e.g., watercolor, acrylic), drying occurs primarily through evaporation of water or solvent.

In oil painting, the process is oxidative polymerization—a chemical reaction in which unsaturated fatty acids in drying oils react with oxygen in the air to form a solid film. This process is slower and depends on pigment type, oil content, temperature, humidity, and airflow.

Ralph Mayer’s The Artist’s Handbook of Materials and Techniques emphasizes that improper management of drying times—especially in oil painting—can lead to structural failures like cracking, wrinkling, or poor interlayer adhesion. For example, pigments such as lead white and umber accelerate oxidation, while ivory black and alizarin crimson are notoriously slow to dry.

In structured painting workflows like those in the Waichulis Curriculum, awareness of these drying dynamics supports strategic layering and consistent material behavior. Respecting appropriate drying times between stages is essential for safe execution of techniques such as indirect painting, scumbling, or glazing. The practice also reinforces critical principles such as ‘fat-over-lean’, which addresses the differential flexibility and drying rates of oil-rich versus leaner paint films​.”

Dry Media

“A class of artistic materials that are applied in a solid, particulate form without the use of a liquid binder during application. Unlike wet media, which rely on a fluid vehicle for pigment delivery, dry media involve direct physical deposition of pigment, binder, or other material onto a surface through friction, pressure, or abrasion. The mark-making agents are typically powdered or waxy solids, held together by minimal binder, and are applied via tools such as pencils, sticks, or blocks. Because they do not flow or absorb into the surface in the same way as wet media, dry media afford artists a high degree of immediate control over pressure, edge, and surface interaction.

Common examples of dry media include graphite, charcoal (both vine and compressed), pastel (soft, hard, or oil), conté, chalk, and colored pencil. These materials are widely used for drawing, sketching, and tonal development due to their responsiveness to pressure modulation, directional mark-making, and erasure. In instructional contexts like the Waichulis Curriculum, dry media are foundational to perceptual training because they allow for refined development of value scales, pressure control, and edge modulation—key elements in developing representational fluency.

Because dry media remain physically exposed on the surface (especially in the case of friable materials like charcoal or soft pastel), they are highly susceptible to smudging, abrasion, and environmental disruption. As a result, dry-media works often require fixatives or protective framing. Surfaces for dry media must also have adequate tooth (surface texture) to hold the medium effectively, which is why materials like mid-value, blue-based charcoal paper are used in formal drawing programs to balance adhesion with erasure capability​.

In summary, dry media are solid, non-liquid materials applied directly through friction, allowing for immediate tactile feedback, a wide range of value and edge control, and iterative development of forms. While offering exceptional control and reversibility, they require careful handling and surface preparation to maintain integrity and stability over time.”

Dry Mounting

“A method of affixing artwork, prints, or paper-based materials to a rigid backing support using heat-activated adhesives rather than moisture-based glues or paste. In this process, a thermoplastic adhesive film—such as a dry-mount tissue—is placed between the artwork and the mounting board. When heat and pressure are applied (typically via a dry-mount press), the adhesive melts and bonds the materials together upon cooling. This method is often favored for its speed, flatness, and resistance to warping or buckling, as no moisture is introduced during the process.

Dry mounting differs from traditional wet mounting in that it does not rely on water-soluble adhesives, thus avoiding the expansion and contraction of paper fibers associated with moisture. However, it is not considered a reversible or conservation-safe practice for valuable or irreplaceable artworks, as the bond created is generally permanent and may alter or damage the original object. In the context of art reproduction, presentation, or instructional environments—such as those in the Waichulis Curriculum—dry mounting may serve practical purposes for stabilizing reference materials, reproductions, or working surfaces where archival reversibility is not a priority.”

Dual-Process Theory

“A foundational model in cognitive psychology that distinguishes between two qualitatively different modes of thinking and information processing: System 1 and System 2. Originally articulated by researchers including Daniel Kahneman and Amos Tversky, this framework has become essential in understanding decision-making, attention, and perceptual interpretation—all of which are critically relevant in visual art training and performance.

System 1: Fast, Intuitive, Automatic: operates rapidly and unconsciously, based on heuristics, habits, and prior experience, responsible for immediate judgments, pattern recognition, and snap interpretations, and efficient but prone to biases, oversights, and false assumptions.

System 1 governs most everyday perception and is the default system for interpreting visual input. In drawing and painting, System 1 may lead to premature labeling (‘that’s an eye’ or ‘that’s an apple’), which can interfere with accurate observation and value/form relationships. The Waichulis Curriculum often refers to this tendency as assumptive interpretation, and counters it with exercises that slow processing and disrupt reflexive shortcuts.

System 2: Slow, Analytical, Effortful: operates consciously and deliberately, engaged during complex reasoning, self-monitoring, and error correction, enables step-by-step problem-solving, calibration, and spatial analysis, and demands attention and energy; easily fatigued or overridden by System 1.

System 2 is often essential for tasks like matching subtle value or color shifts, evaluating complex edge behavior, or executing multi-step comparisons. It is also the preferred mode of processing for deliberate practice, which requires sustained attention, diagnostic feedback, and intentional correction. The Waichulis Curriculum leverages System 2 engagement through structured repetition, check routines, and scaffolded problem-solving, helping learners build cognitive control over instinctive responses and avoid the pitfalls of unexamined heuristics.

The deliberate development of visual fluency requires artists to toggle consciously between both systems—allowing System 1 to automate routine tasks over time, but relying on System 2 for calibration, error detection, and complex visual interpretation. This balance is central to the development of procedural fluency and adaptive expertise.

While System 1 is fast and necessary for efficiency, uncritical reliance on it can lead to perceptual shortcuts and representational inaccuracies. System 2 offers corrective potential, but it must be trained, supported, and practiced—as emphasized in structured perceptual curricula like Waichulis’.

Ultimately, Dual-Process Theory provides a powerful lens through which to understand the cognitive demands of observational art—highlighting how fluency arises not from automatic seeing alone, but from the deliberate regulation and integration of our fast and slow systems of thought.”

Durable / Durability

“The capacity of a material, surface, or construct to maintain its integrity and function over time under expected conditions of use, handling, and environmental exposure. In the context of fine art, especially in painting and sculpture, durability encompasses physical stability, resistance to degradation (e.g., cracking, yellowing, or delamination), and chemical resilience against atmospheric or light-induced deterioration.

Ralph Mayer distinguishes between types of binders and supports based on their intrinsic durability. For example, oil paints, when properly formulated and applied, form tough, elastic, and adherent films through oxidative polymerization—a process that can yield highly durable surfaces if unhindered by improper additives or layering practices. Conversely, certain media like casein or aqueous paints may offer strong initial adhesion but lack long-term durability due to porosity, brittleness, or vulnerability to environmental factors​.

Durability also pertains to structural supports. Materials like rigid panels (e.g., well-braced masonite or aluminum composites) are preferred in contexts like the Waichulis Curriculum due to their dimensional stability and reduced risk of flex-induced cracking—an issue more common with stretched canvas​.

In brushwork and tool selection, durability of fibers (natural or synthetic) ensures consistent performance, resilience under cleaning, and resistance to fraying over time​.

Ultimately, durability is a critical factor in achieving archival quality—an artwork’s ability to remain stable and visually coherent for decades or centuries under standard conservation conditions.”

Dynamic Flow of Visual Elements

“The arrangement of components in an artwork to suggest movement and energy, often intended to encourage the viewer’s eye to travel seamlessly across the composition. While artists may use directional lines, contrasts, and rhythmic patterns to imply a visual flow, Yarbus’ research on eye movement suggests that a viewer’s gaze is primarily influenced by their cognitive intent and the specific task they are engaged in, rather than solely by compositional cues. As a result, while dynamic flow can create perceptual tendencies, it cannot fully dictate how a viewer navigates an image.”

Dynamic Range

“The ratio between the brightest and darkest elements that a visual system, camera sensor, or imaging medium can effectively capture or represent. In perceptual science, it corresponds to the range of luminance levels over which the human eye can detect and differentiate visual information—from the faintest shadow detail to the brightest highlights.

In photography and digital imaging, dynamic range is typically measured in stops (each representing a doubling of light) and determines how well both shadow and highlight detail can be preserved in a single exposure. Modern high-dynamic range (HDR) techniques seek to overcome sensor limitations by combining multiple exposures to increase overall information density across luminance extremes.

In the Waichulis Curriculum, the concept of dynamic range is especially relevant to value scales, gradation exercises, and form development, where a student learns to construct a full perceptual hierarchy of lightness values across a form. Training in charcoal or paint involves controlling pressure and material density to emulate the perceived dynamic range of natural illumination within the bounds of the chosen medium’s physical limitations.

Understanding dynamic range allows artists and photographers to make deliberate choices in compression, contrast allocation, and exposure control—strategies that support the viewer’s perceptual decoding of spatial, structural, and material cues.”

Dynamic Symmetry

“A proportioning system introduced by Jay Hambidge in his 1920 book The Elements of Dynamic Symmetry. The theory suggests that certain geometric ratios, particularly root rectangles (√2, √3, √5), the Golden Ratio (φ), and logarithmic spirals, inherently produce aesthetically superior compositions. Hambidge claimed that Greek art and architecture—particularly during the Classical period—were structured around these proportional relationships, leading to more ‘vibrant and moving’ works compared to the ‘lifeless’ results of static symmetry (based on simple geometric figures like squares and equilateral triangles)​.

Debunking the Claims: A Misinterpretation of Greek Art: Hambidge asserted that the Parthenon and other classical works were designed using Dynamic Symmetry, but architectural measurements do not support this claim. The Parthenon’s base dimensions (69.5 by 30.9 meters) yield a width-to-height and length-to-width ratio of 2.25, which does not match the Golden Ratio or the proposed Dynamic Symmetry root rectangles. While Hambidge claimed that Greek sculptors and painters used these geometric frameworks in ‘almost all art produced’ during the Classical period, no historical documentation supports this assertion​.

Furthermore, a comprehensive 1878 study by Gustav Fechner, which analyzed over 10,000 artworks, failed to demonstrate a preference for Dynamic Symmetry-based proportions​. This aligns with broader empirical aesthetics research, which shows no innate viewer preference for compositions structured around these ratios.

Dynamic Symmetry can indeed seem to ‘work’ Sometimes, as like the Golden Ratio and Rule-of-Thirds, Dynamic Symmetry does not inherently improve composition but may coincide with proven visual biases. Some factors contributing to this illusion include: contrast-driven fixation: high-contrast edges tend to attract attention, making certain compositional grids appear effective, narrative and subject placement: viewers focus on familiar or recognizable subjects, not geometric frameworks, retrospective fitting: supporters of Dynamic Symmetry often apply grids after the fact, forcing an alignment that was never part of the original design process.

Dynamic Symmetry, much like the Golden Ratio, is an overextended mathematical hypothesis that lacks historical documentation and fails empirical testing as an aesthetic principle. While some artists have used it deliberately, its success is not due to any inherent compositional advantage. Instead, artists benefit more from understanding cognitive biases, perceptual psychology, and viewer-driven composition, rather than relying on debunked proportioning systems​.”