Bole is a coloured very fine clay that is used as the immediate surface the gold sits on. It is placed upon the gesso usually with 6-8 coats. Its colour helps to intensify the lustre of the gold and its soft supple nature, will help with burnishing the gold. To make the bole, reheat an appropriate amount of Rabbit Skin Glue (10-1) in a double boiler, ensuring, of course that it does not reach boiling point. Reduce the strength of the RSG by adding approximately 50% water to the mix.
Gradually add bole to the RSG, gently stirring it into the mixture until a 'single cream' consistency is achieved. The best method for this is to scrape a small portion of bole at a time onto the top edge of the container and, using a bristle brush, gradually take a little from the rim and mix it into the rsg in the bottom of the container. Be careful to use a different implement than the brush to collect the bole from the pot, as residues of RSG may be introduced to the bole paste container. If you find it too thin, add a little more until you are happy. Again, the strength comes down to personal preference.