Polyurethane (Task®11 C-1509)

This synthetic resin is a semi-opaque, semi-rigid polyurethane plastic with a milky amber colour, which is similar to cloudy apple juice. It's interesting that it has an amber-like quality, since casting resins were originally named as such by analogy - their behaviour mimicked naturally-occurring tree resins, from which amber is derived. 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. This resin has been approved for use with dry foods. There's some anxiety around the 'migration' of chemicals from plastic used in packaging to food, but with these resins’ migration can only occur with oily foods.