This is a very high quality grade of whiting, used mainly by gilders, to make Sizey White and Gesso. Also by artists to add texture and bulk to paint.
Gesso is a traditional base coat for gilded frames. Once hard and smoothed, coat with Bole.
Gesso - make your own with this recipe:
Fill a 200g coffee jar with cold water. Add 7 heaped teaspoons of rabbit skin glue granules, and leave to soak for at least 4 hours.
Heat in a double glue pot, but never allow to boil. Strain.
Add 6-7 heaped tablespoons of whiting - stir gently to avoid bubbles then strain.
Should keep for up to two weeks in fridge. Apply with round gesso brush - as any metal on the brush may corrode & taint the gesso.