Medium Density Foam

This dense but pliable foam is a most versatile material. It is very lightweight and about 1cm thick. It is made from polyethylene (known as polythene in the UK), the same stuff as shopping bags. Over sixty million tonnes of this material are produced worldwide every year, which is even more than it sounds as it is so lightweight.

This foam is expanded at liquid stage using nitrogen gas, to form a closed cell foam. This means that it is full of individual air bubbles that are not connected, giving the foam a robust, regular structure. If you squash the foam, it will immediately spring back to its original shape, making it a good material for indestructible children’s toys.

It is also a very efficient insulator, machines well and is able to hold a precision edge, and is non-toxic, inert and acid-free, so it won’t react, harbour bacteria or degrade. This makes it ideal for custom cases, for transporting and storing fragile or expensive items, or for medical equipment. It is also easy to cut, shape and glue together by hand which makes it great for building outlandish theatrical costumes as it is super-light and strong, but soft and flexible enough to wear.