Cellophane bags: a thin, transparent sheet made of regenerated cellulose. Its low permeability to air, oils, greases, bacteria, and water makes it useful for food packaging. Cellophane is highly permeable to water vapour, but may be coated with nitrocellulose lacquer to prevent this. Cellophane is derived from natural sources such as wood, while plastic wrap is made from oil. Unlike plastic, cellophane is biodegradable, so it can be composted or sent to a landfill in the regular garbage.