MAJOLICA: Colors (b) Preparing
Preparing and mixing glaze colors: To make up your own glaze colors, mix one portion of color in powder form, which should be the combination of colors needed to produce the desired color, plus three times its volume of transparent glaze. Add water and pass the mixture through a fine sieve. The amounts you make depend on how much you work.
Remember; Keep stirring the glaze colors you are using, this keeps the water and color from separating and maintains a consistent density, which helps the color to run well. Water evaporates, so add more if necessary. If your colors do not run well while painting, add a little medium, which is a lubricant liquid. When the colors are left for a long while, they get dry and hard. Add water, leave for a short while so they can integrate, then mix, using a looped modeling tool. If you stir with a paint brush, be careful as you will not know the density of the color your brush is carrying, so clean the brush before starting to paint.
Note: Medium is the common name for the lubricant and the technical name is Polyethylene glycol