Light-transmitting plastic products now occupy an established place in architecture. In situations where lightweight construction, great resilience and cost economy are required, they offer a number of advantages over mineral glass. No longer the cheap and nasty, yellowing products they were once seen to be, plastics are now an expression of modern technology in architecture. In large part, this?change of image is attributable to their improved quality and the ever-greater number of materials available for the increasing range of uses.