Gall oak

Gall oak is a magical ingredient in magical inks. A dram of powdered gall oak and a dram of gold, added to 7 fl. drs. of giant squid's ink, yield enough ink for up to 7 spells, the ink every scroll is written with. It must be stored in crystal or it loses its power. Gall oak grows in woods and costs 1 G.P. per dram.