carbon typically refers to lightweight and durable materials (resistance to wear and corrosion) like carbon fibre or forged carbon used for cases, dials, or components. For example, the Longines’ Ultra-Chron case was made from strips of unidirectional carbon fibre and epoxy resin. The materials are placed in a mould, heated to a high temperature, compressed under high pressure and cold cut to replicate the shape of the case. The random patterns produced by the carbon fibres make each case unique and contribute to the featherlight weight of the watch.