Vacuum forming is a technique that is used to shape a variety of plastics. In school it is used to form/shape thin plastic, usually plastics such as; polythene and perspex. Vacuum forming is used when an unusual shape like a ‘dish’ or a box-like shape is needed. Below you can see the stages involved in vacuum forming. To the right is an example of a vacuum formed toy. The simple 'lorry' mould has been placed in a vacuum former and a compressed polystyrene sheet has been placed above it. The polystyrene has been heated and then vacuum formed to the shape of the mould. Many everyday items have been vacuum formed in this way. Look around your home - list some examples. as a guide - some food products are packaged in vacuum formed materials.