WPC (Wood Plastic Composite) panels are classically made by blending wood fiber/wood flour with thermoplastic polymers such as PVC plus additives; most WPC wall panels on today's market, however, no longer add wood fiber or wood flour — stone powder and calcium powder are used instead.
There are two formulations by application: interior decorative panels and outdoor-grade weather-resistant panels. Interior panels are usually laminated with PET high-gloss film, PP scratch-resistant film or water-based PVC film in wood grain, marble grain or fabric textures. Outdoor WPC cladding generally uses no film but a different formulation that provides UV resistance and waterproofing.