Prelam is a laminated assembly consisting of plastic sheeting and anti-solar film. The most commonly used sheeting type to date has been PVB, although other types may also be used. The films we use have usually been sputter-coated with metals and/or metal oxides to achieve their anti-solar capabilities. Here again, other varieties of anti-solar films have been and can be explored.

The sheeting and anti-solar film components are most commonly assembled in one of two ways. A bi-layer assembly (supplied almost exclusively to auto glass producers) consists of one layer each of PVB and film. A tri-layer assembly consists of one film layer between two PVB layers.

Laminated glass producers can choose which assembly works best for them based on their own application. For example, if a sputter-coated anti-solar film is to be used, it may be essential for the glass producer to access the film sheet to "cut-back" and seal the film edge from the elements, thereby preventing corrosion. A bi-layer assembly would work best in this case since a tri-layer assembly would completely encapsulate the film. It is also worth mentioning that Crown can produce multi-layer Prelam for specialized uses such as for sound reduction, bullet-resistant glazing and hurricane applications. No matter the assembly, Prelam material is conveniently wound in roll form and can be cut to virtually any width or length.