About 3kg of clay to create a wall as a guide for the plaster and to support the head. About 6kg of plaster. Maybe more… yeah.. it was about 6L of water.
I managed to make this as a one piece mold after all, thank goodness. I was worried about seam flashing and how to support the full mold once made and in two parts… I used my hand as a guide. So long as I can get my hand in the neck opening I’ll be able to clean the clay out and also slush easily once casting begins.