Tannin (Tannin, E181)is a yellow-white dye.
In industry, tannins are used for tanning leather and fur, preparing ink, etching textile fibers, for giving various drinks a tart and astringent taste, and as a food dye.
In medicine, tannins are used as astringent drugs, as an antidote (for poisoning with lead salts, mercury, etc.), as antidiarrheal, hemostatic and antihemorrhoidal agents.