Silicone coated polyester is extremely useful when working with adhesives or whenever you need a non-stick surface. Our single sided silicone coated polyester is made of clear polyester that is 1.42 mil in thickness and is 60" wide. It is coated on one side with a film of silicone. The best way to tell which side of the polyester has the silicone coating applied is to simply take a piece of tape and see to which side it sticks. The side it doesn't stick on is the side with the silicone coating. If you needs are for a wider width material, simplely tape two sections of the release film together.