Lefranc Gilder’s Clay Base, also known as bole, is a clay-like substance applied to a prepared surface, typically Gesso. Gesso is a mixture of chalk (gilder’s whiting) and Rabbit Skin Glue. The combination of the gilder’s clay layer and the underlying Gesso layer creates an ideal surface for polishing gold leaf using an Agate Burnisher Stone. It’s important to note that the gilder’s clay base can only be used on absorbing surfaces.
How to Prepare Lefranc Gilder’s Clay Base:
- Before using Lefranc Gilder’s clay base, it must be prepared with rabbit skin glue before application. The clay is already processed with water to form a paste, but you need to add some rabbit skin glue to it first.
- The typical ratio is one part gilder’s clay to two parts rabbit skin glue (in liquid form), depending on the desired thickness of the clay.
- When adding the rabbit skin glue to the gilder’s clay, ensure that the glue is warm. Mix gently to avoid creating air bubbles until the texture is consistent, runny, and smooth.
- For best results, apply two to three thin coats of this clay onto a perfectly smooth surface, such as Gesso. After the clay has dried, polish it with a Steel Wool Pad or Fibre Cloth until it appears clean, shiny, smooth, and free of dust.
- Next, prepare the gold leaf water using either a Rabbit Skin Glue Tablet or a Pre-made Kölner Colnafix Gilder’s Size. This mixture will slightly wet the clay surface, allowing the gold leaf to adhere.
- Apply the Loose Gold Leaf and let it dry for at least 5 hours. Your gilded surface is now ready to be burnished using an agate burnisher stone.
- To remove any gold flakes that are sitting on the surface, buff gently with a Gilder’s Mop Brush.
- Typically, 24k gold leaf does not require varnishing to protect it from oxidation. However, for gold leaf of less than 24k, it is advisable to use Kolner Leaf Protect Varnish to seal the surface.