A new house has a "sort of" bay window in the front sitting/living room. I always thought of bay windows as having the angled sides, so to me, this is just a "sticks out" window. Nevertheless, it is a perfect spot for a small boy to sit on the windowsill and read a book in the sunshine. So I decided it needed a cushion for the windowsill! I used microsuede for the removable cover, NuFoam for the cushion itself, and muslin for the inner cover. I thought about making a PUL cover like I did for the dog bed, but I decided that might be overkill. No one should be on the cushion with a drink. Anyway, I made this to the sill's measurements, with cutouts in the corners for the edges of the windows. Apparently I goofed slightly - it should be an inch longer. But I can live with that. The cushion is made from two layers of one-inch NuFoam (they didn't have 2-inch at JAF the day I went there, but it's since back in stock, of course), stitched securely together. The muslin cover was made to those measurements and stitched permanently in place - mainly just to make sure the mattress stayed together well. The outer cover was made to the same measurements, but it has cording in the seams to improve longevity. (I made those with bias strips and clothesline.) Instead of installing a zipper - I wanted to have the opening along the inner length, to make it easier to stuff the cushion in place - I overlapped the edges and used my snap press to install a dozen or so snaps along the side. I think it'll work well. Also, I have applied a spray-on UV sunblock to the entire cover in an attempt to decrease fading from the constant sunlight. I tested it on a large scrap, and nothing bad happened to the fabric, so I figured it was safe. ;) And I've kept some large scraps so that I can compare it in a few months and see how well the block worked. Should be interesting!