Plucking

From the foot of a piece, the pulling away of slivers of material that have stuck to the kiln shelf during glaze firing, due to the the clay body (usually porcelain) becoming vitreous/sticky at the maturing temperature. Seriously annoying. The photo above is not the best example, as soda ash from the shino glaze has fluxed the foot ring and made it a wee bit stickier than it might have otherwise been. There are various strategies to prevent this, discussed in this clayart thread. Right now I'm using a little alumina mixed in with wax that I only use for feet and rims, and it does all right.