Bole (Latin for clay) is the coloured clay that, when mixed with rabbit skin glue size, is applied directly to the gesso. It’s main purpose is to seal the gesso layers and provide colour enrichment underneath the gold (which is applied at the next stage). Bole can be visible under gilding that has been abraded or distressed and acts as evidence to indicate provenance or period.
For this Barbizon type frame, we chose a French yellow to cover the surface and a Charbonnel rouge colour was then applied to the areas that would later be water gilded and burnished. Both colours matched the abraded areas of the Maris frame that we used as our guide to making the reproduction.
Once all the bole had been applied and dried, the frame was sandpapered to a mirror-like finish and a coat of glue size brushed onto the surface in preparation for the next stage, the application of loose gold leaf.