Examples from the Web for catechol
The tannins are divided into two general classes, known respectively as the pyrogallol tannins and the catechol tannins.
Of these the catechins are the most typical, and have been considered as the parent substances of the catechol tans.Animal Proteins|Hugh Garner Bennett
"Quercitannic acid," obtained from oak bark, etc., is likewise a catechol tannin.
Tanning materials are divided into two main classes: Pyrogallol, Catechol.Leather|K. J. Adcock
Xanthin and catechol browns are pleasing in appearance, but their effect is less rich than that obtained with potash.The Decoration of Leather|Georges de Rcy