A jelly mould is a mould you may find in the home. It is a hollow container with a special shape. It may have the shape of an animal. Hot liquid jelly is poured into the mould and then left to cool. When the jelly has cooled down, the mould can be turned upside down and the jelly gently shaken out of its mould. The jelly will be in the shape of the mould.

The moulding process for jelly is used to shape other materials. Metals such as bronze or cast iron are heated then poured into moulds to give them special shapes. The bronze may be made into a statue or the cast iron into a car engine.

Glass bottles are made by placing a lump of molten glass in a mould then blowing air into the glass. This makes the glass spread out and cover the inside of the mould. Television screens are made by placing the molten glass in a mould and pressing it to take up the shape of the mould.

Plastic is also shaped by moulding. The liquid plastic may be pushed into a mould and allowed to cool and set to make a plate or bowl, or a sheet of warm plastic may be sucked into a mould to make a plastic cup.