I'm using the blackout fabric from joann's myself. I did end up with one small imperfection off to one side. You can see it if you look just right with the right lighting, but it's invisible under normal viewing conditions.
Carey, I was thinking of using felt for a border, but picked up some 2 3/4" black velvet ribbon at A.C. Moores (a craft shop). Man, does that stuff suck up light like a black hole!