Poliment—also known as bole—is a clay-like substance. It serves as a base layer for the leaf gold when gilding poliment. It is applied to the prepared surface, which is usually Gesso. Gesso is a mixture of chalk and glue. The poliment layer and the underlying layer of Gesso create a layer that permits the polishing of gold with agate burnishers.Poliment gilding can only be used on absorbing surfaces.It is an unbound poliment (unprepared) and has to be prepared with gelatine or rabbit skin glue before it can be applied. This poliment is already processed with water to a paste.Advantages:Very good gradationDoes not pearlExcellent covering powerNeeds little glue