Most paintings are not built from the surface down, they are built from the ground up. Beneath the visible image often lies a hidden structure that determines everything from composition to light. This foundational layer is underpainting. It is not a preliminary sketch or a rough draft; it is a strategic system that governs how the final image will function.
What Existing Articles Cover, and Where They Fall Short
Top-ranking explanations of underpainting typically include:
- A definition (a base layer painted before the final layers)
- Common types (grisaille, imprimatura, etc.)
- Basic instructions for beginners
These are accurate but limited. They tend to present underpainting as a step rather than a system. Missing are:
- How underpainting controls value structure and composition
- Its interaction with techniques like glazing
- Its role in speed, correction, and efficiency
- The difference between visible and concealed underpainting
The result is a procedural overview without structural understanding.
What Underpainting Actually Is
Underpainting is the initial painted layer (or set of layers) that establishes composition, values, and sometimes color relationships before the final image is developed.
It functions as a framework rather than a finished image.
Core Functions of Underpainting
1. Value Structure
Underpainting establishes light and dark relationships:
- Determines contrast and depth
- Clarifies form before color is introduced
- Prevents over-reliance on color for structure
A strong value system can carry the entire painting.
2. Compositional Clarity
It allows the artist to resolve:
- Placement of elements
- Spatial relationships
- Balance and focal points
Adjustments made at this stage are faster and less costly than later corrections.
3. Color Foundation
Some underpaintings influence final color:
- Warm or cool tonal bases shift overall mood
- Transparent layers (glazes) interact with the base
- Color harmony can be pre-established
Color is not applied in isolation, it is built on top of prior decisions.
4. Efficiency and Control
Working out structure early:
- Reduces reworking in later stages
- Allows faster, more confident final application
- Minimizes overpainting and mudding of colors
It is a method of pre-solving problems.
Common Types of Underpainting
1. Grisaille
- Monochromatic (usually grayscale)
- Focuses entirely on value
Function:
Creates a complete light/dark structure before color is added, often used with glazing.
2. Imprimatura
- Thin, transparent wash (often earth tones)
- Covers the white ground
Function:
Reduces glare, establishes a tonal base, and unifies the surface.
3. Verdaccio
- Greenish-gray underpainting used historically for flesh tones
Function:
Neutralizes warm skin colors and creates natural tonal variation.
4. Block-In (Color Underpainting)
- Rough application of major color areas
Function:
Establishes color relationships early, often used in more direct painting methods.
Underpainting vs Direct Painting
Underpainting Approach
- Layered, sequential
- Structure first, detail later
- Often slower but more controlled
Direct (Alla Prima) Approach
- Painted in one pass
- Wet-on-wet blending
- Less reliance on underlying structure
Neither is inherently superior, they produce different results and workflows.
Interaction With Glazing
Underpainting is often paired with glazing:
- Underpainting provides value and structure
- Glazes introduce color and depth
This layered system creates luminosity that cannot be achieved through direct mixing alone.
Material Considerations
Oil Painting
- Ideal for layered systems
- Allows extended working time
- Supports glazing over underpainting
Acrylic Painting
- Faster drying
- Requires planning due to limited blending time
- Still supports layered approaches
The principle remains consistent across mediums.
Structural Misconception: “Underpainting Is Optional”
While not required, omitting underpainting shifts responsibility:
- Structure must be resolved simultaneously with color
- Corrections become more difficult
- Risk of muddied or inconsistent results increases
Choosing not to use underpainting is a trade-off, not a neutral choice.
Visible vs Invisible Underpainting
Underpainting can function in two ways:
- Concealed: fully covered by later layers
- Exposed: intentionally visible, contributing to the final image
In some contemporary work, underpainting becomes part of the aesthetic rather than a hidden structure.
Institutional and Conservation Perspective
Underpainting affects longevity:
- Proper layering improves stability
- Poorly executed bases can lead to cracking or adhesion issues
- Conservators often analyze underpainting to understand an artist’s process
It is both a technical and historical component of the work.
Operational Reality
Underpainting is not about adding an extra step, it is about shifting when decisions are made.
- Early decisions = clarity and control
- Late decisions = correction and compromise
The technique redistributes complexity across the process.
Underpainting is the structural foundation of a painting, establishing values, composition, and often color before the final image emerges. It is not simply a preparatory layer, it is the system that supports everything that follows.
To understand painting fully is to recognize that what is unseen often determines what is seen.