Pigments vs Dyes – What is the Difference?

The Core Difference: Suspension vs. Solution

In simplest terms, the difference boils down to the physics of mud versus sugar-water.

• Pigments are like Mud: When you scoop muddy water, solid particles are suspended in the liquid. Left alone, they will settle. This is a suspension. Pigments are finely ground solid particles suspended in a medium (like water or oil) to create color.

• Dyes are like Sugar: When you mix sugar into water, it dissolves completely, forming a stable mixture that will never separate. This is a solution. Dyes are chemical substances dissolved in a medium.

The key distinction lies in the words “suspended” versus “dissolved.”

How They Work: Surface vs. Bond

This fundamental difference dictates how they interact with materials:

• Pigments coat the surface. The particles sit on top of a substrate (like paper or canvas), physically trapped in its texture or held there by the binding medium (e.g., acrylic polymer, linseed oil). They are not chemically bonded.

• Dyes penetrate and bond. They chemically bond to the material itself, often requiring a mordant to facilitate the process. They become part of the substrate, rather than sitting on it.

Origins and History

• Pigments have natural origins. Early artists used:

  • Umber, Ochre, Sienna: Colored earth from specific regions.

  • Lamp Black: Soot from oil lamps.

  • Ultramarine: Ground lapis lazuli stone.
    Today, most pigments are synthetically manufactured, offering a vast range of bright, stable, and non-toxic colors.

• Dyes were traditionally extracted from organic materials—plants, berries, roots, and insects. Many natural dyes are fugitive, meaning they fade quickly in light. Modern synthetic dyes provide greater color stability and variety.

Practical Application: Why It Matters

Knowing which you’re using is crucial for achieving the desired effect and longevity in your work.

1. Opacity vs. Transparency

   • Pigments are typically more opaque, providing better coverage and light-blocking power.

   • Dyes are inherently transparent, allowing light to pass through for vibrant, stained-glass effects.
     Example: To make glass opaque, use black acrylic paint (pigment), not a black Sharpie (dye).

2. Mixing Colors

   • Mixing Pigments: Often results in muted or muddy colors.

   • Mixing Dyes: Tends to create cleaner, brighter secondary colors.

3. Lightfastness and Stability

   • High-quality pigments offer excellent lightfastness, ensuring your artwork lasts for generations.

   • Many dyes are susceptible to fading when exposed to light, especially sunlight. (This is why art museums have low lighting).

A Guide to Common Products

• Stamp Pads

  • Pigment-Based: Opaque, fade-resistant, slow-drying, won’t bleed through paper. Ideal for watercolor overpainting.

  • Dye-Based: Transparent, vivid, fast-drying, may bleed. Perfect for techniques requiring blending or a stained effect.

• Markers

  • Dye-Based: The majority of markers, including permanent markers (Sharpie), alcohol-based markers (Copic), and highlighters. They are transparent and can bleed.

  • Pigment-Based: Paint markers, acrylic ink markers (Montana), and some archival drawing pens (Pigma Micron). They are opaque, waterproof, and lightfast.

• Inks

  • Dye-Based: Most alcohol inks (Ranger), fountain pen inks, and Dr. Ph. Martin’s Radiant watercolors.

  • Pigment-Based: India ink, acrylic inks (Liquitex, Daler Rowney FW), and Dr. Ph. Martin’s Bombay India inks.

Pro Tip: You can create custom, lightfast acrylic markers by filling empty Copic-style marker bodies with pigment-based acrylic ink. This is excellent for drawing on non-porous surfaces like polymer clay.

Understanding the difference between pigments and dyes empowers you to choose the right material for opacity, permanence, and effect, ensuring your creative vision stands the test of time.