In the second part of this series, Stephen Koob, the Museum’s conservator, describes the methods used to fill the losses of a prunted beaker on display in Medieval Glass for Popes, Princes, and Peasants.
Now that the beaker has been reassembled, Koob uses plasticine to first create a backing for the losses. Plaster of paris is mixed and poured carefully on top of the backing, creating a perfect match for the loss. The plaster “piece” is then removed and a mold made of it using silicone rubber. Koob uses epoxy resin to create a cast of the actual fill piece. Acrylic adhesive is used to put the fill piece in place and, with a little clean-up, the result is a fully restored, structurally stable piece.