Polyurethane (Clear Flex 50)

This is a transparent urethane liquid rubber that picks up the detail of the mould into which it is cast with great clarity. Because it's so impressionable and easily cast, this material is often used for making prototypes, props and decorative cast pieces. Unlike some of the discoloured polyurethane swatches in this collection, this material is pretty inert and stable under UV light so it doesn't degenerate in sunlight. Regardless of the end-product or even type of polyurethane you are using, the way in which you use polyurethane resins is always the same: the raw materials come in two parts, a liquid isocyanate (a very reactive chemical derived from petroleum) and a polyol (a long-chain alcohol), which are mixed to a specified ratio to create a reacting liquid, which is then poured into a mould or onto a surface and left until it cures to form a solid object.