The cork oak grows in the Mediterranean region. The cork is actually bark. The cork oak grows thick layers of corky bark which can be stripped off the tree without harming it. The cork is then boiled and pressed to make it more elastic.

A major use of cork is as a stopper in wine bottles. It has two useful properties for this task. It is elastic and can be squeezed into the top of the bottle. When squashed in this way air cannot pass through it. This is extremely useful as wine quickly spoils if air can reach it while it is being stored.

Toughness is another property of cork and this can be seen when a wine bottle is opened. A corkscrew has to be turned into the cork using some strength and then pulled hard to remove the cork from the bottle.

The insulating property of cork is used to make table mats.

Some floor tiles are made from cork. The cork's toughness allows it to be walked on without tearing. Cork is also a heat insulator so it is comfortable to walk on with bare feet. Cork floor tiles do not feel as cold as other kinds of floor tiles.

Cork may also be used as wall tiles. Here it is the tiles' attractive appearance that makes them useful but they also provide some heat insulation and absorb some sound.

Cork is so light in weight that it floats well on water. This property has made it a useful material for lifebelts and floats for fishing nets.