Most of my frames have Acrylite OP-3 in them. It blocks 98% of UV light. The windows in my condo are also tinted, blocking out a substantial percentage of UV light. I don't use a lot of interior lights in my condo, and most interior lights other than halogens do not emit a lot of UV light anyway - but even a low level on for significant amounts of time would obviously not be good. Luckily, my windows are all facing North (one is slightly Northwest), so being in the Northern Hemisphere, there is usually no direct sun light in my condo. Taking these factors into consideration, I am confident that my posters will not fade much, if it all. It just boils down to how far you want to go with protecting them. They can sit in a drawer, box, etc. forever and not suffer damage, or they can be framed and appreciated, possibly being slightly damaged a little bit even if precautions are taken. Personally, I'd say if it's not the Mona Lisa or something like that, then take a few preventive measures, and don't get too worked up over it, but that's just me.