To obtain a coloring material by baking an animal protein fiber under a fixed condition.

The method utilizes thermal denaturation of animal protein and provides a coloring material having various color, which can be regulated by the length of a process of decomposing an animal protein, under a condition of nonoxidative atmosphere using a vacuum type furnace. An animal protein fiber is used as a raw material because variation of time and temperature changes color and enables to obtain an aimed material and also because of the understanding that it becomes fine grain by heating easier than the other fibers. Although the fabric of an organic pigment is prescribed in general that it is a colored powder soluble neither in water nor in oil, the coloring material made by the method is easily dispersible in solvent and sheds a soft color different from other azo-, indigo-based pigments etc. which may result in chemical reaction, and when in case of mixing with other materials the material fit to a required color even when the compounding ratio is very small, moreover because the material has been subjected to a physical grinding treatment it does not give damage to its characteristics and can be used quite trustfully.