The Gypsemna’s Normal (RG ) Sort C Gypsum Board is an insides gypsum board comprising of a strong set, Sort C gypsum center encased in GRAY-colored confront paper and a solid liner back paper. Gypsemna’s RG Sort C board. Long edges are marginally decreased, permitting joints to be fortified and concealed with joint tape and joint compound. The confront paper and the back paper are 100 percent reused.