A majority of architectural grade window film on the market will block up to 99% of harmful UV rays that cause damage to flooring, walls, and furniture in homes and offices.
Keep in mind two factors that cause fading:
UV rays are primarily responsible for fading, but they only account for 40% of the problem. Combined with infrared radiation (IR) or heat at 25% and visible light at another 25%, you have a recipe for fading. The remaining 10% of fading is caused by naturally, physically, or chemically occurring factors. This includes vapors and off-gassing, wear and tear, the age of fabrics or woods, and dye fastness.
While no window film can completely block 100% of the UV rays and fully prevent objects from fading naturally, it will slow down the process of fading dramatically thus preserving your property much longer than without window film.