Coating foamed products

A foamed product, particularly a prosthesis or medical model, is produced by colouring an open-celled foamed material using a colourant contained within a liquid carrier medium such as hexane. After evaporation of the liquid carrier medium, the coloured foamed material is impregnated with a silicone which is cured to form a silicone coating over the interiors of at least the cells adjacent the surface of the foamed material.