Paint Making

Part of Pigments and Paint

The complete paint-making process from raw materials to finished product.

Why This Matters

Paint is not a luxury — it is a critical infrastructure material. Without paint, wooden structures rot, metal equipment rusts, and communities lose the ability to create permanent signage, maps, and instructional diagrams. Every civilization in history developed paint-making because the alternative — constant rebuilding and replacement of unprotected structures — wastes labor and materials on a massive scale.

The complete paint-making process involves four core steps: sourcing pigments, processing them into fine powder, selecting and preparing a binder, and combining pigment with binder into usable paint. Each step has well-established techniques that work with materials found in nearly any environment. Understanding the full process end-to-end lets you adapt when specific materials are unavailable.

This article provides the complete overview — the forest rather than the trees. Detailed techniques for each stage are covered in the companion deep-dive articles on specific topics like grinding, levigation, and individual binder types.

The Four Components of Paint

Every paint consists of four elements:

Component	Function	Examples
Pigment	Provides color and opacity	Ochre, charcoal, malachite, chalk
Binder	Holds pigment particles together and adheres them to the surface	Linseed oil, egg yolk, lime, hide glue
Vehicle	Carries the paint and controls flow (usually evaporates)	Water, turpentine
Additives	Modify properties (optional)	Driers, thickeners, preservatives

The simplest possible paint is pigment mixed with water and a binder. Everything beyond that is optimization.

Step 1: Sourcing Pigments

Mineral Sources

The most durable pigments come from minerals and rocks:

• Yellow ochre: Iron-rich clay or soil — yellowish-brown deposits near streams, road cuts, or eroded hillsides
• Red ochre: Red-brown soil or hematite nodules. Can also be made by heating yellow ochre
• White: Chalk (limestone), kaolin (white clay), or ground eggshells/seashells
• Black: Charcoal from hardwood, soot from oil lamps, manganese dioxide ore
• Brown: Raw umber (manganese-iron earth), raw sienna (iron earth)
• Green: Malachite (copper ore areas), green earth (celadonite/glauconite — widespread but dull)
• Blue: Azurite (copper ore areas — rare and precious)

Biological Sources

Plants and animals provide supplementary colors:

• Plant-based: Woad or indigo (blue), madder root (red), saffron (yellow), various berries (temporary inks)
• Animal-based: Cochineal insects (brilliant red), cuttlefish ink (sepia brown), bone char (black)
• Limitation: Most biological pigments fade in light. Use for interior work, manuscripts, and temporary applications

Synthetic Sources (Produced by Chemical Reaction)

Some pigments can be manufactured:

• Lime white: Slaked lime dried to powder — very white, alkaline
• Burnt ochres: Heating yellow ochre produces red; heating raw umber produces warm brown
• Lamp black: Soot collected from burning oil or resin — the purest carbon black
• Verdigris: Copper exposed to acetic acid (vinegar) vapors produces a blue-green crust

Step 2: Processing Pigments

Raw pigment materials must be transformed into fine, uniform powder before mixing with binder. The standard processing chain:

Crushing

Break raw material into pea-sized pieces using a hammer, heavy rock, or mortar and pestle. For hard minerals, wrap in cloth first to contain flying fragments.

Washing and Levigation

Suspend crushed material in water to separate pigment from sand, gravel, and organic contaminants. Let coarse impurities settle first (30-60 seconds), pour off the cloudy water containing fine pigment, then let that settle for hours. The resulting sediment is purified pigment. See Levigation for the full process.

Calcination (Heat Treatment)

Some pigments are improved or transformed by heating:

• Yellow ochre heated to 300-400 degrees Celsius becomes red ochre
• Raw sienna becomes burnt sienna (deep orange-brown)
• Raw umber becomes burnt umber (warm reddish-brown)
• Bones heated in a sealed container become bone black

Fine Grinding (Mulling)

The final and most important step. Using a muller on a flat stone slab, grind the dry pigment with a small amount of water into an ultra-fine paste. This may take 15-45 minutes depending on pigment hardness. The goal is a perfectly smooth paste with no detectable grit. See Grinding Techniques.

Step 3: Selecting a Binder

The binder determines the paint’s durability, finish, working properties, and appropriate uses:

Binder	Durability	Water Resistance	Drying Time	Best For
Linseed oil	Excellent	Excellent	2-5 days	Exterior wood, metal, boats
Walnut oil	Very good	Very good	3-7 days	Light-colored paints
Egg yolk (tempera)	Very good	Moderate	Minutes	Panels, signs, fine detail
Lime (fresco/wash)	Exceptional	Good	Hours-days	Masonry, walls, permanent murals
Hide glue (distemper)	Moderate	Poor	Hours	Interior walls, ceilings
Gum arabic	Moderate	Poor	Minutes	Manuscripts, watercolor-style work
Casein (milk paint)	Good	Moderate	Hours	Furniture, interior wood

Matching Binder to Application

Exterior/weather-exposed surfaces: Oil binder only. Nothing else withstands sustained rain and sun exposure.

Interior walls: Limewash (cheapest, disinfecting), casein/milk paint (moderate durability, pleasant matte finish), or distemper (hide glue — economical, washable).

Signage and diagrams: Egg tempera on prepared panels (durable, detailed) or lime fresco on plaster (permanent).

Metal protection: Oil paint is the only practical option. Apply over a primer coat.

Fine detail work: Egg tempera (fast drying, thin lines possible) or watercolor-style gum arabic paint.

Step 4: Mixing Paint

Basic Procedure

1. Start with finely ground, dry pigment on a clean flat surface
2. Add binder gradually — the amount varies by pigment and binder type
3. Work the pigment into the binder with a palette knife, then grind with a muller
4. Continue mulling until perfectly smooth — 10-20 minutes for most combinations
5. Adjust consistency: add vehicle (water or turpentine) to thin; add pigment to thicken
6. Test on a scrap surface before committing to your project

Consistency Guide

Application	Consistency	How to Test
Primer/sealer	Thin — like milk	Flows freely from brush, semi-transparent
General coating	Medium — like cream	Covers in 2-3 coats, smooth flow
Detail painting	Thick — like soft butter	Holds brush marks, full coverage in one coat
Thick coating/filler	Paste — like putty	Applied with knife, gap-filling

Recipes for Common Paints

Exterior White Paint (Oil-Based)

• 100g chalk white (ground and levigated)
• 30-40 ml linseed oil (processed or sun-thickened)
• Turpentine to thin as needed
• Mull pigment and oil on slab until smooth. Thin with turpentine for first coat, use with more oil for topcoat

Red Barn Paint (Casein/Milk Paint)

A traditional economical exterior coating:

• 1 liter skim milk (casein source)
• 100g red ochre
• 50g lime putty
• Mix lime into milk (forms calcium caseinate binder). Add ochre and stir thoroughly. Apply to raw or previously painted wood. Surprisingly durable for a water-based paint

Interior Wall Paint (Limewash)

• Aged lime putty
• Water to thin to milk consistency
• Pigment (up to 10% by volume) for color
• Apply 3-5 thin coats to masonry or plaster

Workshop Signage (Egg Tempera)

• 1 egg yolk
• Equal volume of ground pigment
• Water to thin to painting consistency
• Apply to gesso-prepared wooden panels

Rust-Preventive Metal Coating (Oil-Based)

• 100g red ochre (iron oxide protects iron — counterintuitive but effective)
• 35-40 ml boiled linseed oil
• Mull together. Thin first coat with turpentine. Apply 2-3 coats to clean, dry metal

Scaling Production

For community-scale paint production:

1. Pigment station: Dedicated grinding area with multiple slabs and mullers. Assign workers to continuous grinding
2. Oil processing: Establish a linseed oil press and processing facility. Sun-thicken oil in batches during summer months
3. Batch mixing: Mix paint in larger quantities using wooden troughs and heavy mullers. A single batch should supply a day’s work for a painting crew
4. Standardization: Develop standard recipes and keep written records of ratios and sources. Consistency between batches matters for uniform appearance
5. Storage: Store excess paint in sealed containers. Oil paint keeps for weeks under oil seal. Limewash keeps indefinitely. Tempera must be mixed fresh daily

Quality Control

Before applying any paint to a finished surface, test:

1. Coverage: Does it cover the surface evenly in 2-3 coats?
2. Adhesion: After drying, does it stick firmly? Can you scrape it off with a fingernail?
3. Flexibility: On wood, does it crack when the wood flexes?
4. Color: Is the dried color what you expected? (Most paints lighten or darken as they dry)
5. Durability: Expose a test patch to weather for a week. Does it hold up?

Keep test patches as references for future batches. Consistency in paint production saves enormous rework.