Here are some "facts" and "myths" about fading:
Myth: If you block UV, things will not fade any more.
Fact: No product will stop fading. UV blockers (present is window film and other applications) will reduce fading to some degree.
Myth: Only UV is responsible for fading.
Fact: UV is only one component of fading. Other major contributing factors are heat and light. Some fading is caused by other environmental factors, but generally only a small contribution.
Myth: Fade reduction can be given as a percentage.
Fact: Every material or colour is affected in different ways, so a fade reduction of 85% may be possible in one particular fabric, of a specific colour. A different material or colour will give a different result. For example, dark leather and fabrics discolour more than light colours. The question is: A given percentage of fade reduction is based on what?
We feel, a rating system of stars, or "good, better, best" is more appropriate than giving products a specific %. Having said this, any product on the market only blocking UV can be rated "good" only, no more. In order to get "better", or "best" results, the heat and light issues must be addressed. Even then, fading will still occur, but at a much slower rate.