Made from seaweed, this remarkable material is used to make precision moulds for making casts of body parts. When the fine white powder is mixed with water, it turns purple and then changes colour to indicate readiness for moulding around a pattern, and then setting. It takes just minutes to create a durable flexible mould capable of taking plaster, plastics and low temperature metals. The material is entirely natural and non toxic, and has a very low cost compared to other high definition mould making materials such as silicon compounds.