Ingredients and equipment
- Rabbit skin glue (RSG)
- Whiting (Chalk)
- Bole – red and yellow clays
- Gold leaf (loose)
- Gilder’s cushion, knife, tip, mop, burnisher
- Brandy or similar, to taste
a) Size: The first layer to cover the substrate (wood or whatever) is a 1:12 mixture of rabbit skin glue and water. Leave this overnight, then heat in a bain marie to hand-hot and brush onto the substrate.
b) Gesso: 1:6 RSG: Water. Having soaked overnight, put in heatproof container, preferably clear (Pyrex or similar). Sift the whiting, and then sprinkle it into the rsg until the pile of chalk comes to just under the top. This way around should eliminate as much air as possible, and air is to be avoided, for it has a nasty habit of making your gesso go pockety and bumpy. Therefore, stir carefully.
Using a damp, but no soaking wet, brush, paint the gesso on, building up coats (at least 8, and probably more like 12 coats), leaving half an hour or so between coats. (If you return to this the following day, wipe a damp cloth over the gesso before you start.)
The gesso will become thicker as the day goes on; add more water as necessary.
Once hard, smooth the gesso with sandpaper (240, 320, 600, 1200) or, if feeling really expert, with a damp cloth.
If a raised, decorated surface is required, build it up out of gesso, smoothing it at the end of this process.
c) Bole: The two main boles used for gilding are yellow and red – yellow tends to be the base, and red for the relief or highlit bits. Mix 1:12 size with some bole to the consistency of single cream. Paint on; it will take about 3 coats to turn the item yellow. Smooth this with the back of wet-and-dry sandpaper or with a cotton cloth – you don’t want it to be too abrasive.
d) Applying the gold leaf: This requires a draught-free space and a lot of patience. (A swig of brandy might be necessary.) With the knife, put a leaf on the gilder’s cushion, so that it is flat and as wrinkle-free as possible.