Oak Gall / EikenGal / EicheGallen / Galas / Galle du Chêne

Gallnuts from the oak tree are the earliest and richest source for natural tannin. They are produced by insects who deposit their eggs in small punctures they make on young branches. As a protection, the tree excretes a tannin-rich substance that hardens and forms into a gallnut. These are collected and ground for use as a tannin mordant. Gallnut or Oak Gall is used to mordant cellulose fibers and fabrics before the alum mordant is used. Alum does not combine as readily with cellulose fibers as it does with protein fibers. Tannin has a great affinity with cellulose fiber and once mordanted with tannin, alum combines well with the tannin-fiber complex. Oak Gallnuts is abnormal outgrowths of plant tissues caused by various parasites, particularly insects. Oak galls, found on oaks in the Middle East, have long been used to make high-quality ink and for dyeing.  The tannic acid is perfect for the pre-treatment of cellulosic vegetable fibers.