Have you ever noticed how much of our food comes in tins - soup, tomatoes, sardines, baked beans and much, much more? Why is this? Well, tins are a very good way of packing food that we don't want to eat straight away because they keep it fresh. Tins are sealed and don't let any air get to the food. This means that food in tins can last for months, even years, without going off. They are also very strong, protecting food while it is being delivered to shops or carried home.

They are called 'tins' because they are made of a metal called tin. Tin is excellent for keeping food in because it doesn't go rusty like other metals, which would make the food dangerous to eat. Nowadays tins are often made from cheaper, lighter metals like steel or aluminium, and then coated in tin to protect the food inside.

Tins were first used for food in 1814, when the British sent food to their army in them. Before this people in the army used to often get ill from eating food that wasn't fresh. Tins were a cheap and easy way of giving them fresh food. Because the tin opener hadn't been invented, they would have to open them with knives, or even a hammer and chisel!

Since then, not many things have changed. Tins are such a simple and good design that not many improvements can be made to them. One important development was the invention of the ring pull. This meant that tins can be opened without a tin opener, and also made them very popular as drink containers.