A composition is disclosed that comprises rigid PVC and from about 0.1 to about 10 phr of an EPM copolymer. The compositions optionally also include one or several additives selected from lubricants, impact modifiers, process aids, fusion promoters, heat stabilizers, co-stabilizers, fillers, pigments, antioxidants, UV absorbers, antistats, metal release agents, and plasticizers. The EPM is particularly useful as a PVC gloss reducing agent and additive enhancing agent for such polymer additives, particularly lubricants, heat stabilizers, UV absorbers, and pigments.