Philosophy, Chemistry of Pigment
Pigment as Philosophy, Chemistry as Craft
Every painting is a conversation with light. But light alone isn’t enough.
It needs a partner, something to dance with. That partner is pigment.
What we call “color” is not just hue. It’s the behavior of matter under light. It’s the size, shape, and structure of pigment particles, each one a microscopic world dictating how a surface speaks to your eyes. In encaustic, this relationship is heightened. Because here, the pigment doesn’t just sit in a binder, it’s suspended in light-bearing wax, fused by flame, and preserved like an insect in amber.
If encaustic is alchemy, pigment is the philosopher’s stone.
Organic vs. Inorganic Pigments:
Opacity, Strength, and the Hidden Geometry of Color
Inorganic pigments (e.g., ochres, oxides, titanium white):
Heavier, more opaque, chemically mineral-based. These pigments have high refractive indices, excellent lightfastness, and are naturally more scatter-prone, leading to strong hiding power.¹Organic pigments (e.g., phthalocyanines, quinacridones):
Carbon-based, lab-developed pigments with vibrant colors and high tinting strength. These are often more transparent due to lower refractive indices and finer particle size.²
The distinction isn't just chemical, it's metaphysical. Inorganics are the bones. Organics are the fire.
Particle Size and Dispersion:
How Small Shapes Change Everything
All pigments begin as primary particles, often less than one micron in size. These particles are agglomerated into clusters for storage, then separated through dispersion, the act of evenly distributing pigment throughout a binder.³
Smaller particles = more surface area = more interaction with light
Larger particles = more scatter = increased opacity
In encaustic, where the medium is already translucent, this dance becomes more dramatic. Pigment doesn't just color the wax—it collaborates with it.
Crystal Structure and Polymorphic Hues
Pigments are crystalline materials, not just powders. The way molecules align within their structure affects how light is reflected or absorbed. Some pigments (like titanium white or ultramarine) may share chemical formulas but display different hues due to polymorphism, variation in crystal formation.⁴
These microstructures give color its voice.
Two blues. Same chemistry. Different soul.
Purity and the Haunting Beauty of Flaws
Synthetic pigments are engineered for purity, performance, and consistency.
Natural pigments, mined from the earth, carry impurities, trace minerals, organic content, soil memories that make each batch unique.⁵
These "flaws" are not defects. They're stories.
Ultramarine made from lapis lazuli in Afghanistan looks different than the same stone mined in Chile. Each sample is a visual accent of its geography, a mineral fingerprint of deep time.
Why Pigment Science Matters for Artists
This is not about perfection. It’s about intimacy with your medium.
When you understand how particle size affects transparency, or how crystal structure affects hue, or how a pigment refracts light inside wax—you become fluent in the secret language of color.
“To know your pigment is to know your spellcraft. You are not just layering wax. You are distilling light, bending perception, resurrecting earth.”
Footnotes
Gettens, R. J., & Stout, G. L. Painting Materials: A Short Encyclopaedia. Dover Publications, 1966.
Berrie, Barbara H. (ed.). Artist's Pigments: A Handbook of Their History and Characteristics. National Gallery of Art (Vol. 4).
Kühn, Hermann. “Conservation and Restoration of Paintings.” Scientific American, 1979.
Eastaugh, Nicholas et al. Pigment Compendium: A Dictionary and Optical Microscopy of Historical Pigments. Routledge, 2008.
Thompson, Daniel V. The Materials of Medieval Painting. Dover Publications, 1956.