Polyurethane (Clear Flex 95)

This polymer feels slightly more resistant and brittle than the Clear Flex 50 sample when you bend it, but it is also quite elastic so it quickly reverts back into its cast shape when let go. Unlike some of the discoloured polyurethane swatches in this collection, this material is quite inert and stable under UV light so it doesn't degenerate in sunlight. This urethane liquid rubber has relatively low-tech requirements since it cures at room temperature. As such, it can be very useful for tinkering and making prototypes. 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.