1. Make a simple mould by pressing a coin or some other pattern into plasticine (modelling clay). Carefully peel the plasticine away and mount it on a flat surface with the image of the coin facing up.

2. For the next part you should wear gloves, and work on some newspaper so you don't make a mess, and get an adult to help you.

3. Following the directions on the pack of body filler, you mix a tiny amount of hardener with some (monomer) resin. Mix it really thoroughly so that you make a good reaction.

4. Carefully spread the mixed up filler over the plasticine mould.

5. While the filler is going hard, gently feel the temperature. If it is warm, it is a sure sign of a chemical reaction taking place.

6. Leave your filler to go really hard. If you try to look at it too soon you might break it.

7. Carefully peel the plasticine away, and you will have your own reaction moulded article.