Lots of great ideas here. Thanks for sharing your experiences. I copied them and put them in a file on my desktop so I can use them later when I move. I had been using a flannel backed tablecloth or a piece of white flannel (same issue as mentioned above as to strings bugging me; never thought of black though.) The flannel was on a rod using round spring clip curtain rings and worked well when I could pin it stretched tighter on both sides, otherwise, it moved and swish, there the blocks would go, on their own trip around the room.