Excellent back light. Enhances dimensionality. (Trans.= 10%). (Transmission = 10%).Co-extruded polycarbonate, the majority of Roscolux is colored all the way through the plastic. Raw polycarbonate is combined with dye pellets in a powerful extruder. The heat and pressure of the extrusion process thoroughly combine the clear plastic and the dye resulting in a plastic that is body colored all the way through the film. To further insure the durability of the color, a very thin layer of clear polycarbonate is then applied to both sides of the colored film, trapping the color between and providing a protective barrier. The final film then is extremely resistant to color fading, more durable to the high heat of lighting fixtures and protected from minor scratches and abrasions.