Gold Bond® BRAND 5/8" SoundBreak® XP® Gypsum Board with Sporgard™ has an acoustically enhanced, high density fire resistant Type X gypsum core encased in a heavy, abrasion and mold/mildew/moisture resistant, 100% recycled, National Gypsum PURPLE® paper on both sides. Used in the construction of high rated STC wall assemblies, this 5/8" thick gypsum board consists of a layer of viscoelastic damping polymer sandwiched between two pieces of high density mold resistant gypsum board, providing constrained layer damping.