Our first activity was to try making vine tendril charcoal for our black pigment. Muirghein found the reference in Theophilus, and Portia cut the dry vine tendrils from a dead grape vine. As there was no specific recipe for how to create this charcoal, we then took them to Sui to get some help, and he walked us through the process of creating charcoal from the vine tendrils.
Essentially charcoal is created by burning something in a restricted space - in this case a milo tin that had been used before to create charcloth. We packed the tin as full as possible of vine tendrils, placed the lid on it with a small hole, and then put it on the barbecue. As the tendrils heated, they off-gassed, and this caught fire - you know your substance has become charcoal when this fire goes out.
At the end of the process, we tested the blackened tendrils in a small brazier with a flint and steel to check that we had definitely created charcoal. Success! Now to make the pigment by grinding it all up...