Moulds of a clay base enclosed in flexible plastic film - for obtaining non-planar optical effects in simulated stained glass windows

摘要

A mould comprises a rigid frame pressed onto two layers to flexible film which lie on a layer of modelling clay. A third layer of flexible film lies beneath the modelling clay. The frame can be pressed on to the base to lie in local depressions, with the clay and film displaced to form convex surfaces. Concave faces on the cast resin surfaces produce divergent optical effects. Flexible PVC or polyethylene films are pref. used as the flexible films.