the burnishers are made of an Agata stone on a brass ferrule and varnished wooden handle. They are available in various stone shapes and sizes; they may be used on all the surfaces, both smooth and corrugated.
The Agata burnisher is a professional tool, made of the highest quality materials, which is used to press the gold leaf, once it is dried, onto the bole underneath.

The extremely smooth surface of the Agata stone allows to fix and polish the gold leaf, which becomes as a whole with the base of gesso and bole.