Roll covering materials are often called roll lagging. Their purpose is to provide a specific surface for a roll. Usually this means a gripping surface. As can be seen from the photograph, lagging comes in various materials. Some of these are PVC, natural rubber, cork, and other plastics. The surface of the lagging can be smooth, rough, dimpled, or even have nibs sticking out. Lagging is usually 2 or 3 inches wide. It can come with adhesive on the back or it can have a cloth backing and must be glued onto the roll with special contact adhesive. The photo on the left shows white plastic, cork, natural rubber, and green PVC lagging.
It is very important to keep the lagging in good condition so no damage occurs to the fabric.