Bole clay is used to prepare the surface for Water Gilding. It is coloured to provide a base colour should any of the gold leaf wear away and will tint the extremely thin leaf. This skilled technique allows for the gold leaf to be burnished to a mirror shine and provides the best results for objects gilded with precious gold. Bole is also used for illuminated gilding on manuscripts and religious artefacts. The technique is suitable for interior use only, use Oil-based Gold Size for outdoor items such as signs and garden ornaments.
Sinopia Clay Bole is a wet clay which when combined with Rabbit Skin Glue is painted over a surface prepared with Gesso, also made from Rabbit Skin Glue combined with Calcium Carbonate. The dried bole clay is sanded, smoothed and cleaned very carefully to ensure there are no flaws. When water is applied to the dried clay bole, the surface becomes tacky so that the gold leaf will stick to it. After the clay has dried, the gold is burnished to simulate pure solid gold.