I normally use gouache or watercolour paints, prepared in small dishes or used directly from the tube.
If I want a richer colour, I use pure pigments. These are ground in a pestle and mortar and mixed with a binder, such as gum arabic or animal glue. I’ll usually also mix them with some rice paste glue on the block itself.
Colour is evenly brushed in a thin layer onto the woodblock, then left until it appears to start to dry. At this point, a sheet of the dampened paper is put in position with the aid of a registration guide.
A thin piece of paper, or plastic, is placed over the paper to be printed; then carefully but quickly rubbed over with a baren.
This process is repeated for each colour, building up the image in layers. For a rich saturation, apply the same colour again.