tannins

Updated: June 24, 2025

Then of wood colours we have further: quercitron, Persian berries, fustic and the tannins or tannic acids, comprising extracts, barks, fruits, and gallnuts, with also leaves and twigs, as with sumac. All these colours dye only with mordants, mostly forming with certain metallic oxides or basic salts, brightly-coloured compounds on the tissues to which they are applied.

Watson Smith - The Chemistry of Hat Manufacturing: Lectures Delivered Before the Hat Manufacturers' Association

The chemical composition of wood and of minor forest products, such as tannins and dye stuffs, is important; the properties governing the fuel value and the other values of wood must be studied, as well as the methods of using these properties in the making of charcoal and wood pulp, in wood distillation, the turpentine industry, in tanning and dyeing, and in other industries.

Gifford Pinchot - The Training of a Forester