I don't have a lot of windows, but had folded t-shirts displayed in the front near the windows. I experienced fading only on a couple of colors where the fold was exposed to the light. I've moved them more to the center of the store and started rotating merchandise that is displayed in or near the windows. I try to rotate at least once a month and haven't seen much of a problem since. I have considered using a film to cover the windows -- can't remember the name of it right now, but I think you can buy it at any hardware store. You can still see through it from both sides, but it shades the sun.