I use 2 ladders: one is very tall and I have larger quilts on that one and the other one is an old bunk-bed ladder with a couple of small quilts on it. I also have 3 on my couch and 4 hanging on walls. My very early (and bad) quilts are on a wooden rack in my sun-porch; they get some sunlight but haven't faded in the 10 yrs they've been out there.
I do put acid free paper on all the wooden rungs of the ladders and rack I use.