Kydex is a thermoplastic which becomes flexible (and moldable) above a specified temperature and solidifies when cooled. It is widely used in the process of heat press molding and vacuum forming to make everything from knife sheaths to molded airplane cabin fixtures. Black craft sheets come in variety of thicknesses and have a gloss finish on one side and a lightly textured finish on the other.  These sheets are ideal for crafting holsters, sheaths and wallets.