Oak bark

White oak Quercus alba

Description

The bark from several species of oak contains up to 14% water-soluble dyes and tannins. The wood also contains tannins but in smaller quantities. Oak tannins contain pyrogallol and condensed tannins. They have a neutral pH, a moderate salt content and are used to produce a fine, heavy leather. Oak bark extracts are also used for dyeing. They produce colors ranging from black (black oak, quercitron) to rose-tan (red oak) to khaki (white oak). Oak dyes have good fastness to light and washing.

Synonyms and Related Terms

casca de carvalho (Port.); oak extract

Authority

• G.S.Brady, G.S.Brady, Materials Handbook, McGraw-Hill Book Co., New York, 1971 Comment: p. 556

• Matt Roberts, Don Etherington, Matt Roberts, Don Etherington, Bookbinding and the Conservation of Books: a Dictionary of Descriptive Terminology, U.S. Government Printing Office, Washington DC, 1982

• Dictionary of Building Preservation, Ward Bucher, ed., John Wiley & Sons, Inc., New York City, 1996

• F. Crace-Calvert, F. Crace-Calvert, Dyeing and Calico Printing, Palmer & Howe, London, 1876