As plastics can be moulded into any shape, objects can be designed and manufactured to help consumers understand how to use them instinctively: without instructions. The shape of the object can represent something else that the user is experienced in using, for example, the slide viewer shaped like a television screen will be peered at without question, and the pepper grinder has the appearance of a wing nut, an industrial fastening which is turned by hand. Alternatively, the ring pull aid looks just like the drinks can opener it is designed to help open.
Metaphoric designs can instantly tell us the contents of an object without the use of text based description or instruction. The tomato shaped bottle would hold tomato ketchup, the biscuit shaped container is designed to house biscuits, and the Jelly Baby jar contained the well-known sweet.
Plastics ability to create illusions through metaphor and skeuomorphism is epitomised by the Illusion table created by heating a sheet of acrylic and laying it over a former like a table cloth over a café table.