The second reason to use an overlaminate is to protect the printed image from abrasion and other elements. The inks can be easily scratched when not laminated.
The use of an overlaminate also allows customers to change the finish on a printed graphic. Manufacturers offer a variety of finishes from matte to luster and high gloss. This allows the customer to choose the best finish for the type of graphic they are producing.
The added thickness of the overall product when laminated also makes the product easier to handle during the installation process.