When you buy something in a shop, you will normally be given a bag to put it in. Bags are a very useful type of packaging because they make it easier for you to carry things you buy. They all seem to be fairly similar - they have handles and a big 'pocket' area to put things in. However, there are actually many different varieties. The shape and design of a bag depends on what is going to be put in it. This is why different shops have different types of bags.

If you buy a sandwich or a burger, you will probably get it in a paper bag. Paper bags are small, don't have handles and aren't very strong. This makes them perfect for take away food which is small and light enough to carry by just gripping the bag.

If you buy shopping from a supermarket, you will usually put it in carrier bags. Carrier bags have handles and can carry quite a lot. Although they are made from very thin plastic they are fairly strong. Carrier bags are very cheap to make, and supermarkets have them because they give so many away.

It is important to re-use carrier bags because throwing them away isn't very good for the environment. When you unload your shopping at home, keep the empty bag and use it again - maybe take your lunch to school in it. Some supermarkets sell better quality, stronger bags that you can use again and again. These are better for the environment.

If you buy something a bit more expensive - clothes or shoes for example - you often get a bigger and stronger carrier bag than you do at the supermarket. Your shopping probably isn't any heavier at the supermarket, so why is this? Well, for a start clothes and shoe shops don't use as many bags as supermarkets, so they can afford to buy better ones. Also, the bags will often have the name of the shop on them. When you leave the shop, people will see the bag and the name. If the bag looks good, people are more likely to remember the name of the shop and visit it themselves. When you go down the street with a bag that has a shop's name or logo on it, you are a walking advert!

Logos and the way packaging looks are very important.