PolyOpaque - A4 PolyOpaque cover material made from high-quality, recyclable polypropylene protects and enhances A4 documents permanently. The material features a smooth side and a lightly sand-textured side and is available in various colors. It protects against stains and scratches, making it ideal for frequently used documents. Made from environmentally friendly, recyclable polypropylene. Strong: made from durable, 300-micron thick, waterproof polypropylene. PolyOpaque covers protect your documents from stains and wear. Available in A4 and A5 sizes. Choose from 5 classic business colors: White, Black, Blue, Dark Red, and Dark Blue.