Paper transfer is a process in which a DECAL is used to transfer a design or pattern from one surface to another. A DECAL is a thin piece of paper with a design or pattern printed on it, which can be transferred to another surface by using water or heat. The DECAL is usually made of vinyl or plastic and is often used for decorative purposes. It is also used in the printing industry to transfer designs onto products such as t-shirts, mugs, and other items.