CertainTeed Type-X fire-resistant drywall is an interior gypsum board consisting of a solid set, fire-resistive, Type-X gypsum core enclosed in ivory colored face paper and a strong liner back paper. CertainTeed Type-X board features a specially formulated core providing fire resistance ratings when used in tested assemblies. Long edges are slightly tapered, allowing joints to be reinforced and concealed with joint tape and joint compound.