Pigments and Paint
Why This Matters
Paint protects structures from rot, rust, and weather. It waterproofs boats, preserves wood, prevents iron from corroding, and makes surfaces cleanable. Beyond protection, pigments give you ink for printing, color for signage and maps, and the ability to mark territory, label containers, and create visual communication that works at a distance. Every civilization developed paint early because it is simultaneously practical and essential for organizing society.
Pigment vs. Dye: The Critical Difference
A dye dissolves in liquid and chemically bonds to fibers. A pigment does not dissolve — it is a finely ground solid particle that sits on a surface, held in place by a binder (oil, egg, lime, or glue). This distinction matters because:
- Dyes are transparent; pigments are opaque (they cover what is underneath)
- Dyes soak into material; pigments sit on top as a film
- Pigments need a binder to stick; dyes bond chemically on their own
- Pigments can coat any surface (wood, stone, metal, plaster); dyes only work on absorbent fibers
Sourcing Pigments
Earth Pigments (Ochres)
The easiest pigments to find. Any clay-rich soil with a strong color contains usable pigment.
| Pigment | Color | Source | Abundance |
|---|---|---|---|
| Yellow ochre | Yellow to gold | Iron-rich clay (limonite) | Extremely common worldwide |
| Red ochre | Red to rust | Heated yellow ochre or natural hematite clay | Common; also made by heating yellow ochre |
| Burnt sienna | Warm reddish-brown | Heated raw sienna (iron-rich earth) | Heat raw sienna to 300-400 C |
| Raw umber | Cool brown | Manganese-rich earth | Found near wetlands |
| Burnt umber | Dark warm brown | Heated raw umber | Heat raw umber to 300-400 C |
| Chalk white | White | Chalk deposits, limestone, crushed shells | Abundant in limestone regions |
Step 1 — Dig colored earth or clay. Look for exposed banks, streambeds, and cliff faces with strong yellow, red, or brown coloring.
Step 2 — Dry the earth completely in the sun. Break into small lumps.
Step 3 — Grind to a fine powder using a mortar and pestle or by rubbing between two flat stones (a muller and a slab).
Step 4 — Levigate to remove grit. Mix the powder with water in a jar. Stir vigorously and let settle for 30 seconds. Pour off the still-cloudy water into a second jar — this carries the finest pigment particles. Let the second jar settle completely (hours to overnight). Pour off the clear water. The sediment at the bottom is your refined pigment. Dry it.
Tip
To convert yellow ochre to red ochre, heat it in a fire to 300-400 degrees C. The iron hydroxide (limonite) converts to iron oxide (hematite), shifting the color from yellow to red permanently. This is the oldest known pigment transformation — used by humans 100,000 years ago.
Mineral Pigments
These require finding specific minerals, but they produce vivid colors unavailable from earth pigments.
| Mineral | Color | Where to Find | Toxicity |
|---|---|---|---|
| Malachite | Green | Near copper deposits; green-banded stone | Low (wash hands) |
| Azurite | Blue | Near copper deposits; deep blue crystite | Low |
| Cinnabar | Bright red | Mercury sulfide deposits | HIGH — toxic mercury; handle carefully |
| Orpiment | Yellow | Volcanic regions, hot springs | HIGH — contains arsenic |
| Chalk/gypsum | White | Limestone regions, evaporite deposits | None |
Warning
Cinnabar and orpiment are beautiful but dangerously toxic. Cinnabar contains mercury; orpiment contains arsenic. Grind them outdoors, wear a cloth over your face, wash hands thoroughly after handling, and never use them on food containers, children’s items, or anywhere they might be ingested. Prefer ochre-based alternatives unless the vivid color is essential.
Carbon Pigments (Black)
Lampblack (finest quality): Hold a smooth ceramic plate or metal sheet in the flame of an oil lamp or candle. Soot collects on the surface. Scrape it off. This produces the finest, most intense black pigment. It takes patience — expect to collect about 5 grams per hour of burning.
Charcoal black: Grind hardwood charcoal to a very fine powder. Coarser than lampblack but available in quantity. Best results come from vine charcoal (willow or grape vine burned in a closed container).
Bone black: Burn animal bones in a closed container (not in open air) until they are completely black. Grind to powder. Produces a warm, slightly brownish black. Also called “ivory black.”
Grinding and Processing Pigments
The Muller Method
Professional-quality pigment grinding uses a muller — a heavy, flat-bottomed stone — on a grinding slab.
Step 1 — Find or shape a flat stone slab (granite, marble, or any hard non-porous stone) at least 30 cm square. The surface must be flat and smooth.
Step 2 — Shape a muller: a palm-sized stone with a flat bottom and rounded top that fits comfortably in your hand.
Step 3 — Place a small amount of dry pigment on the slab. Add a few drops of water or binder. Press and rotate the muller across the pigment in circular motions. The weight of the muller crushes particles between the flat surfaces. Continue until the pigment feels completely smooth between your fingers with no grit whatsoever.
Step 4 — For the finest results, levigate after grinding: suspend the ground pigment in water, let coarse particles settle for 30 seconds, pour off the suspension containing only the finest particles.
Calcination (Heat Treatment)
Heating pigments changes their color permanently:
| Starting Material | Heating Temperature | Result |
|---|---|---|
| Yellow ochre | 300-400 C | Red ochre |
| Raw sienna | 300-400 C | Burnt sienna (reddish brown) |
| Raw umber | 300-400 C | Burnt umber (dark chocolate) |
| Chalk + iron filings | 800 C | Venetian red (deep red) |
| Bone | 400-500 C (closed) | Bone black |
Binders: What Holds Pigment to Surface
Pigment without a binder is just colored dust. The binder is the liquid that carries the pigment, then dries or cures to form a hard film that locks the pigment to the surface.
Linseed Oil
The most important paint binder in history. Pressed from flax seeds (the same plant used for linen).
Step 1 — Crush ripe flax seeds in a press or between stones. Collect the oil.
Step 2 — Let the oil settle, then pour off the clear oil from the sediment.
Step 3 — For faster-drying paint, “boil” the oil: heat it gently (do NOT actually boil — keep below 150 C) for several hours until it thickens slightly. This is “stand oil” and it dries faster and harder than raw linseed oil.
Warning
Linseed oil does not dry by evaporation — it cures by absorbing oxygen from the air. Rags soaked in linseed oil can spontaneously combust. Always hang oily rags to dry spread out, or submerge them in water. Never ball them up or leave them in a pile.
Egg Tempera
Egg yolk is an excellent binder that dries quickly and produces a hard, durable surface.
Step 1 — Separate the yolk from the white. Roll the yolk sac on your palm to dry it, then puncture it and squeeze the yolk into a container. Discard the sac.
Step 2 — Mix the yolk with an equal volume of water. This is your tempera medium.
Step 3 — Mix with pigment on your grinding slab. Use enough medium to make a creamy paste. Paint in thin layers — tempera cracks if applied too thickly.
Casein (Milk Paint)
Casein is the protein in milk. It produces a matte, chalky finish that is surprisingly durable.
Step 1 — Warm skim milk (or non-fat milk) and add vinegar or lemon juice until curds form. Strain out the curds.
Step 2 — Press the curds dry. Mix with a small amount of slaked lime (calcium hydroxide) — about 1 part lime to 5 parts curd by volume. The lime makes the casein soluble.
Step 3 — Add water to reach a paintable consistency. Mix in pigment.
Lime (Whitewash and Fresco)
Slaked lime mixed with water is the simplest, cheapest binder. See Lime and Cement for how to make it.
Step 1 — Mix slaked lime with water to a thin, creamy consistency (roughly 1 part lime paste to 3-4 parts water).
Step 2 — For plain whitewash, this is your paint. Apply with a broad brush. Two to three coats.
Step 3 — For colored lime paint, add pigment. Only alkali-resistant pigments survive in lime: earth pigments (ochres, umbers, siennas) and carbon black. Do NOT use malachite, azurite, or other mineral pigments — lime’s alkalinity will destroy them.
Making Paint: Recipes
Oil Paint (Exterior, Durable)
Best for: wood siding, doors, shutters, boats, outdoor furniture, metal protection.
Step 1 — Place a tablespoon of finely ground pigment on your grinding slab.
Step 2 — Add linseed oil drop by drop, grinding with the muller after each addition. The pigment will absorb oil progressively. Keep adding oil and grinding until the mixture is a smooth, creamy paste with no dry spots and no excess puddles of oil.
Step 3 — Thin with turpentine (distilled from pine resin) if needed for easier brushing. Start with 10-20 percent turpentine by volume.
Step 4 — Apply in thin, even coats. Allow each coat to dry completely (2-7 days depending on temperature and humidity) before applying the next. Two to three coats provide full coverage and protection.
Whitewash (Interior/Exterior, Cheap)
Best for: walls, ceilings, fences, barns, food storage areas (lime is mildly antiseptic).
Step 1 — Mix 1 part lime putty with 3-4 parts water.
Step 2 — Add a handful of salt (improves adhesion and hardness).
Step 3 — For a tougher finish, add a cup of skim milk or casein solution.
Step 4 — Apply 3-4 thin coats with a wide brush. Each coat looks transparent when wet but dries white. Reapply annually.
Tip
Whitewash is mildly antiseptic — lime kills bacteria and mold. This is why dairy barns, chicken coops, and food cellars were traditionally whitewashed. It is not just cosmetic; it is a sanitation tool.
Protective Wood Finish (No Color)
Step 1 — Mix 2 parts linseed oil with 1 part turpentine.
Step 2 — Warm the mixture gently (do NOT heat over open flame — turpentine is flammable). Warm oil penetrates wood more deeply.
Step 3 — Apply liberally to clean, dry wood with a brush or rag. Let soak for 20-30 minutes, then wipe off excess.
Step 4 — Allow to cure for 3-5 days. Apply 2-3 coats total. This waterproofs the wood and prevents cracking, splitting, and rot.
Rust-Preventive Paint
Step 1 — Grind iron oxide (red ochre) finely. This is your pigment — it is the same chemical as rust, so it bonds chemically with the iron surface.
Step 2 — Mix with linseed oil as described above for oil paint.
Step 3 — Clean the metal surface thoroughly — remove all existing rust with a wire brush or sandstone. The surface must be dry.
Step 4 — Apply two coats of the red oxide paint. This is the traditional “barn red” and “bridge red” paint — chosen not for aesthetics but because iron oxide pigment in oil produces the most durable, most rust-resistant coating available from natural materials.
Making Ink
Iron Gall Ink
The gold standard for permanent writing ink. See Natural Dyes for the full recipe. The short version:
Crushed oak galls + water (soak 3-7 days) + iron mordant (rusty nails + vinegar) + gum arabic = permanent blue-black ink that bonds chemically with paper.
Carbon Ink (for Printing)
Printing ink must be thicker and stickier than writing ink.
Step 1 — Collect a large quantity of lampblack (soot from oil lamps).
Step 2 — Mix with boiled linseed oil (thickened by heating). The ratio is roughly 1 part lampblack to 3-4 parts thickened oil.
Step 3 — Grind on your slab with the muller for at least 30 minutes. Printing ink must be perfectly smooth — any grit will damage the printing surface.
Step 4 — The ink should be tacky, not runny. It should pull away from your finger in strings. If too thin, add more lampblack. If too thick, add a drop of oil.
Color Mixing Principles
You can create any color from a limited palette of pigments:
| Mixing | Result |
|---|---|
| Red ochre + yellow ochre | Orange |
| Yellow ochre + charcoal black | Olive green |
| Azurite + yellow ochre | Green |
| Red ochre + chalk white | Pink |
| Any color + chalk white | Lighter tint |
| Any color + charcoal black | Darker shade |
| Red ochre + charcoal black | Dark brown |
| Yellow ochre + red ochre + charcoal black | Warm gray |
Tip
Always add the darker pigment to the lighter one in small amounts. It is far easier to darken a color than to lighten one. A tiny amount of black dramatically changes any color; add it a pinch at a time.
Making Brushes
Step 1 — Collect animal hair. Hog bristle is stiff (good for oil paint and whitewash). Squirrel, badger, or horse tail hair is softer (good for fine work and tempera). Alternatively, use plant fiber — split and softened ends of fibrous sticks.
Step 2 — Tie a small bundle of hair tightly with thread or fine cord. The working end should be roughly 2-3 cm long for a standard brush.
Step 3 — Insert the tied bundle into a ferrule — a small tube of metal, bone, or tightly wrapped bark. Push the hair in firmly.
Step 4 — Insert a wooden handle (a straight stick) into the other end of the ferrule. Wedge or glue it tight.
Step 5 — Trim the bristle tips to a flat edge (for broad work) or leave natural taper (for fine work). Soak in water before first use to soften the hair and help it hold paint.
What’s Next
With pigments and paint mastered, you can move on to:
- Printing — use your pigment-based inks for movable-type or block printing
- Woodworking — protect finished wood projects with oil finishes and paint
Pigments and Paint -- At a Glance
Pigment vs. Dye: Pigment = insoluble particles held by binder. Dye = dissolved color bonded to fiber.
Easy Pigments from Nature:
- Yellow ochre (iron-rich clay) — heat to 300 C for red ochre
- Charcoal/lampblack (soot) — finest black
- Chalk/crushed shells — white
- Malachite (copper ore) — green
Four Main Binders:
Binder Drying Time Best For Key Property Linseed oil 2-7 days Exterior, wood, metal Most durable; waterproof Egg tempera Minutes Interior, fine art Fast-drying; hard finish Lime (whitewash) Hours Walls, barns, sanitation Cheapest; antiseptic Casein (milk) Hours Interior walls, furniture Matte; hard when cured Processing Steps:
- Dig/collect raw material
- Dry and crush
- Grind fine with muller on slab
- Levigate (water-settle) to remove grit
- Mix with binder to paint consistency
Safety Rules:
- Never pile linseed-oily rags (spontaneous combustion)
- Grind toxic minerals (cinnabar, orpiment) outdoors with face covering
- Only use alkali-resistant pigments in lime wash