In the summertime the farmer cuts off the sheep s fleece. The fleece is then spun and made into WOOL. Clothes made from wool keep us warm. Clothes are made from lots of different materials. Some materials, like leather, are made from animal skins. Cotton and linen are made from plants. Other materials, such as polyester, are called 'man-made materials'. This is because they are not made from animal skins or plants.