How to make manuscript gesso
Several people have contacted me over the past week asking me where I buy my manuscript gesso from. The answer is that it is not, as far as I am aware, commercially available here in the UK, so I make my own.
Here’s the recipe:
8 parts of slaked plaster of Paris (calcium sulphate dihydrate)
3 parts of powdered lead carbonate – BEWARE, POISONOUS
1 part seccotine glue
1 part sugar, ground to a powder
A pinch of Armenian bole to colour the mixture
Distilled water to mix.
Measure all the ingredients with a measuring spoon, levelling the dry powders off with a palette knife. I mix my gesso on a granite slab. It is possible to make gesso with a mortar and pestle (not one that you are going to use for food preparation!) but it is more difficult to get it completely smooth.
Mix, then add the measure of seccotine glue, taking care to scrape all the glue out of the measuring spoon.
Add a little distilled water, then mix all the ingredients together. Wear a mask so that you minimise the amount of lead dust you inhale.
Grind with a muller until completely smooth, adding more distilled water as required. There should be no lumps of powder remaining.
The whole process takes 1 1/2 to 2 hours, but the good news is that the gesso can be dried and kept for future use – just spoon small amounts on to an acetate sheet and allow to dry in a dust-free environment. Always wash your hands after you have finished and clear up responsibly. I do not allow any lead to be washed down the sink.
When needed, simply take a little gesso and re-constitute it with water.