Polyester does not get wrinkled easily. It remains crisp and is easy to wash. So, it is quite suitable for making dress material. PET is a very familiar form of polyester. It is used for making bottles, utensils, films, wires and many other useful products. Sweaters and shawls or blankets that we use in winter are made of a synthetic fibre called acrylic. The wool obtained from natural sources is quite expensive, whereas clothes made from acrylic are relatively cheap. They are available in a variety of colours.