Indicated by Giorgio Vasari (1568), it is one of the most noted boles for its utilization in gilding procedures in order to facilitate the adhesion of gold leaf to a gesso-prepared surface. It is red in colour more or less intense according to the quantity of iron oxide included in the contents. Available in powder, pieces, and blocks, the Armenian bole is dissolved in water or is mixed with egg whites and diluted with water in order to then be applied with a brush. Precise indications on its use are furnished by Cennino Cennini.