There are essentially two reasons to use an overlaminate: (1) to protect the printed graphic from damage, and (2) to add aesthetic qualities. In terms of protection, an overlaminate can extend the life of the graphic by shielding it from environmental factors such as abrasion, sunlight, moisture and chemicals. In terms of appearance, an overlaminate can add a gloss, matte, textured or other visual finish to the final product to provide added appeal.

There are a multitude of overlaminating options to choose from based on your application requirements. The most common overlaminating films include polyester, vinyl, polycarbonate, polypropylene, and fluoropolymers. Specific end-use requirements will dictate which type to use.

• Polyesters (PETs) can be ideal in terms of providing heat, abrasion and UV resistance. Standard PETs typically provide protection for up to two years, while specialty PETs offer protection for up to five years and can even protect graphics printed with less-durable inks. 
• Fluoropolymers offer excellent UV resistance, and some also add graffiti resistance. They are often used for outdoor advertising applications.
• Polycarbonate overlaminates offer a velvet-textured look, but they can be pricey. Some matte polyesters can offer a similar velvety look without the high price tag. In addition, polyesters can withstand outdoor use, whereas polycarbonates will degrade with UV exposure.
• Polypropylenes (PPs) provide good chemical resistance, particularly to acids, making them a good choice for automotive battery applications. They can be used for personal care applications where some additional protection is desired; however, UV varnish is usually the treatment of choice. Surfaces that may see a lot of abrasion. 
• Vinyl overlaminates are prized for their flexibility, vinyl's are only recommended when used over another vinyl labels, because vinyl will shrink. vinyls are very conformable and will adhere to compound curves while offering up to seven years of outdoor protection.