I needed three different backdrops for the Let the Ghoul Times Roll black light party for Festivities magazine: one for the drinks station, one for the dessert table, and one for the favors table. The fastest and easiest of the three (though they were all pretty darn simple) was the one for the favors table.
The antique windows, with their chipped paint, had exactly the haunted-house, architectural kind of vibe I was looking for, without being too spooky.
I bought the fabric from Joann Fabrics for just a few dollars, and simply cut out a square of the fabric and hot glued it on the back of the window frame.
It's worth noting that I used a low-temperature glue gun. The fabric is a sheer, tulle-like fabric and you will glue your fingers as you smooth down the fabric and glue it to the wood of the window.
I also found it easier to cut the fabric generously (larger than you'll need), glue it down, and then trim away excess fabric rather than try to cut it to fit perfectly.
Simple, easy, and inexpensive! Well, especially inexpensive if you bought the antique windows for a Butterfly birthday party a year and a half ago, and have had them lurking in the garage, just waiting for a chance to get re-used. But I only paid about $25 for those windows the first time, so it's still not outrageously expensive. Still, I'm very glad I had the chance to use them again. I love recycling party elements in new ways!