Each piece of Formcard is a plastic rectangle roughly the size of a credit card, but thicker. You drop one into boiled water, fish it out, let it cool a little and you’ve got yourself a sticky plastic mess that feels like a blob of chewing gum. This gummy blob works well as a hybrid of glue and putty, and sets hard once it’s cooled. If you make mistakes with it, you can peel it up, reheat it and try again, which is very handy. You get three pieces in a pack, and it’s relatively simple to use, although it does have some drawbacks. The first is that it’s near impossible to make any external repair look nice with it, even if the colour matches. Secondly, it requires a lot of squashing and prodding to use. As the last resort of the jury rigger, though, it’s a helpful addition to a toolkit.