1/2"-4x8' XP® - MOLD/MOISTURE RESISTANT DRYWALL | The Gold Bond 1/2 in.- 4 ft. x 8 ft. PURPLE XP Regular Gypsum Board is GREENGUARD gold Certified and features 100% recycled purple paper on the face and back sides. This regular gypsum board resists fire, mold and moisture for durability. The PURPLE XP gypsum board also features tapered edges for smooth joints.