Ready-made watercolours are convenient, but making a small batch from dry pigment reveals what the paint actually is: finely divided colour held together by a water-soluble binder. The process is modest in scale, though it rewards patience. A little pigment, a little gum arabic, and steady grinding can produce a paint with its own particular flow, granulation, and strength.
This method is intended for artist-grade pigments and a small quantity of paint. Begin with one forgiving pigment, such as ultramarine blue, before attempting difficult colours. The proportions below are starting points rather than fixed recipes, since pigments differ greatly in density, absorbency, and particle size.
What watercolour paint is made from
Traditional watercolour consists chiefly of pigment and gum arabic, diluted with water. The pigment supplies colour; gum arabic binds the particles and allows the dry paint to be rewetted from the palette. A small amount of glycerine or honey may be added to keep the paint from becoming excessively brittle and to help it rewet, though too much can make it sticky or slow to dry.
Distilled water is useful because it contains fewer dissolved minerals than tap water. It makes a clean, predictable starting point for the binder and paint mixture.
A note on pigment safety
Treat dry pigment as a fine dust, not as an ordinary household powder. Read the manufacturer’s safety information before opening it, and do not use pigments of uncertain origin. Some pigments contain hazardous metals or other substances. Work with good ventilation, avoid creating airborne dust, and wear suitable eye and respiratory protection. Do not sweep spilled pigment or blow it from the work surface; damp wiping is safer.
Keep pigment, tools, and finished paint away from food preparation areas. Wash hands carefully after working, and label every jar or pan with the pigment name and pigment index where supplied.
Materials and preparation
You will need:
- artist-grade dry pigment
- gum arabic solution
- distilled water in a dropper or small bottle
- a glass slab or other smooth, non-porous surface
- a glass muller
- a palette knife
- a small spatula or pipette
- glycerine or honey, if required
- a small airtight pan or jar
- gloves, eye protection, and suitable dust protection
A gum arabic solution can be made by combining one part gum arabic with two parts distilled water by volume, then allowing it to dissolve fully. Strain it if undissolved pieces remain. Commercial gum arabic solution may also be used; check its consistency, since prepared solutions vary.
Clean and dry the slab, muller, knife, and containers before beginning. A trace of another colour can noticeably change a small batch of paint.
How to make watercolour paint
1. Measure a small amount of pigment
Work with a small quantity while learning. Place the pigment on the glass slab and gather it into a low mound. Make a shallow hollow in the centre with the palette knife.
Do not begin by pouring in a large amount of binder. It is easier to add liquid gradually than to correct a thin, over-bound mixture.
2. Add the gum arabic solution
Add a few drops of gum arabic solution to the hollow. For a first trial, ultramarine blue may begin close to a one-to-one relationship between pigment and binder by volume. Other pigments may need considerably more binder; a ratio near one part pigment to two parts binder is sometimes a useful starting point for colours that do not readily incorporate.
These figures are not rules. Dense pigments may need less liquid, while absorbent or bulky pigments may need more. The aim is a thick, workable paste rather than a pourable liquid.
Use the palette knife to fold the dry pigment into the binder. Scrape the edges inward until there are no obvious dry pockets. If the mixture remains powdery, add binder one drop at a time. If it becomes runny, add a little more pigment.
3. Mull the paste
Set the muller over the paste and move it in small circles, pressing firmly but evenly. Lift the muller occasionally and scrape the paint back to the centre with the knife. Continue until the mixture becomes smooth and uniform.
Mulling breaks apart aggregates and distributes the pigment through the gum solution. It is not simply mixing: the repeated pressure changes the texture of the paint. Some pigments become smooth quickly, while others need prolonged work. Do not judge the colour only by looking at the wet pile. Draw a small stroke on watercolour paper to see whether it disperses evenly.
Keep the paste together. If the slab begins to look dry, add a drop of distilled water or binder as appropriate. If the paint spreads too freely beneath the muller, scrape it up, allow it to thicken briefly, and continue with less liquid.
4. Adjust the consistency
When the paint feels smooth, inspect it for dry specks, streaks, or a sandy drag beneath the muller. Continue grinding if necessary. A slight grain may be a natural feature of a granulating pigment, but unwanted lumps usually indicate incomplete dispersion.
At this stage, add only a very small amount of glycerine or honey if the paint dries hard and refuses to rewet. Begin with a drop for a small batch and mix thoroughly. Too much can leave the paint tacky, attract dust, or make brush handling unpleasant.
A good working consistency is similar to a thick cream or soft paste. It should hold a low mound briefly but spread under the knife without crumbling.
5. Test before filling the pan
Make three simple tests on good watercolour paper:
- Dilute the paint generously and look for an even wash.
- Paint a concentrated stroke and check for weak coverage, excessive gloss, or cracking.
- Let a small sample dry, then try to lift it with a clean, damp brush.
If the paint beads on the paper, it may contain too much binder or may need more thorough mixing. If it dries powdery and lifts entirely, it may need more gum arabic. If it forms hard cracks or becomes difficult to rewet, a small amount of glycerine or honey may help, though the underlying problem may simply be insufficient binder or excessive drying.
Make only one adjustment at a time and retest. It is easy to lose track of the mixture when several changes are made together.
6. Fill and dry the paint
Use the palette knife or a small spatula to transfer the finished paint into a clean half pan, full pan, or small airtight jar. Press it into the corners and tap the container gently on the table to release trapped air.
Leave the container open in a clean, protected place until the paint has set. Drying too quickly can encourage cracking, while a damp room may leave the surface soft for longer. Once the paint is dry, close the container and store it away from heat and direct sunlight.
Some handmade watercolours shrink as they dry. If the pan has a deep hollow, add another thin layer after the first has settled rather than filling it in one heavy pour. This can reduce large cracks and makes the paint easier to rewet.
Common mistakes to avoid
Using too much binder
A glossy, rubbery paint that slides across the paper often contains more gum arabic than it needs. Add pigment gradually and mull it thoroughly rather than trying to dilute the mixture with water.
Skipping the mulling stage
A palette knife can combine the ingredients, but it cannot always break down pigment aggregates. Paint that looks mixed may still produce a streaky wash or gritty marks. Time spent with the muller is usually the most important part of the process.
Choosing an unsafe pigment
Avoid unlabeled powders, industrial colourants, and pigments intended for uses other than artists’ materials. Never assume that a natural-looking pigment is harmless. Keep the original label or record the pigment name and safety information with the finished paint.
Making too much at once
Small batches are easier to correct and less wasteful. They also let you compare different binder levels without committing a large amount of pigment.
Failing to label the pan
Write the pigment name, pigment index if known, date, and any additions such as honey or glycerine on the container or its storage box. Handmade colours can look very different when wet and dry, and unlabeled pans quickly become difficult to identify.
A practical first batch
For a first attempt, choose one artist-grade ultramarine blue and make a modest paste with gum arabic solution added a few drops at a time. Mull until the colour is even, test a diluted wash, and fill only one or two small pans. Record how much binder was used and how the paint behaves after drying.
That record becomes more useful than any universal ratio. With each pigment, note whether it settles heavily, needs extended mulling, dries glossy, cracks, or rewets easily. Over time, these observations form a personal paintmaking reference suited to the materials and paper you actually use.
Making watercolour paint is a quiet process of adjustment. The useful measure is not whether the mixture follows a perfect formula, but whether the dry pigment has been safely and thoroughly dispersed, the binder is sufficient without being excessive, and the finished colour behaves well under the brush.