Most gouache pigments are relatively transparent, composed of powdery materials, fixed with glue, and have strong coverage. So when drawing gouache, I often draw from the darkest colors.
Can be covered layer by layer. If you have patience, you can also paint the same effect as an oil painting, but when the paint is wet, the color is darker, and the color becomes lighter when dried. There are also purple ones such as rose red and violet which are easy to turn out. So it is not used as a base. The color particles of gouache pigments are very fine, and the color is very beautiful after being dissolved in water, but it cannot cover the background color. The colors of ultramarine, ocher, and red of watercolor pigments are mineral pigments, which are easy to precipitate when used alone or mixed with other colors.
Various binders are required to make gouache pigments.
Colorant——Using ball mill to grind into very fine pigment powder.
Filler-mainly various white pigments or wheat starch.
Glue-dextrin, gum, etc.
Wetting agent-rock sugar, glycerin, etc.
Preservatives-carbolic acid or formalin.