Clay, also know as Bole is used in traditional water gilding process. The bole is mixed with rabbit skin glue and applied to the prepared surface before laying down the gold leaf.
This bole is made in USA by Sinopia.
A 4 oz jar weighs about 200g
A 16 oz jar weighs about 800g
A 32 oz jar weighs about 1500g
All these are the very traditional colors that have been used in gilding industry over centuries.