For those thinking about fading (which is a given), I would recommend using the same type of fabric that's used for drapery lining, like a light colored muslin, broadcloth, or canvas as the backer that would be closest to the glass. Fading would be less noticeable.
On the other hand, if you don't line and it fades, we're talking about a couple of little tiny projects here and you could just plan on replacing every so often with some other jazzy new fabric.
I'll get these done when I can (recovering from bunion surgery which is why I'm inside on the computer on a beautiful summer Sunday!) and post photos.
