Any colour that can be obtained in a fine dry powder may be used in wood-block printing. Some artists have succeeded in using ordinary water colours sold in tubes, by mixing the colour with the rice paste before printing; but the best results are obtained by the use of pure, finely ground dry colour mixed only with water, the rice paste being added actually on the block.

Most of the artists' colour merchants supply colour by weight in the form of dry powder: any colour that is commonly used in oil or water-colour painting may be obtained in this state. A stock of useful colours should be kept in wide-necked bottles.

A few shallow plates or small dishes are needed to hold colour and a bone or horn palette knife for mixing and rubbing the colour into a smooth paste in the dishes. Small bone paper knives are useful for taking colour from the bottles.

When the colour scheme of a print is made certain—and this is best done by printing small experimental batches—it is a good plan to have a number of covered pots equal to the number of the different colour impressions, and to fill these with a quantity of each tint, the colour or colours being mixed smoothly with water to the consistency of stiff cream.

Some colours will be found to print more smoothly and easily than others. Yellow ochre, for instance, prints with perfect smoothness and ease, while heavier or more gritty colours tend to separate and are more difficult. In the case of a very heavy colour such as vermilion, a drop of glue solution will keep the colour smooth for printing, and less paste is necessary. But most colours will give good impressions by means of rice paste alone. It is essential, however, that only very finely ground colours of good quality should be used.