Haven't needed any for a while, but I bought them from Double Bull in the past. I believe one piece was big enough to cover two windows, and one just tucked the extra material under the blind poles to hold them in place. Pretty expensive for what it is, however, so I now "stretch" the material by cutting it to fit the windows more closely. That way, the same piece of fabric will cover three windows. I use small safety pins to pin them in place. Sometimes fabric stores or sporting good stores sell the same kind of mesh/cheesecloth type camo material, but I don't see it around here very often. Good luck.