I make quilts for dog shelters. Use everything ... upholstery fabric, denim, heavy cotton, cordoroy, polyester. I make them using 8" - 12" squares, half triangles, etc. and practice blocks. Don't put batting in them but a couple had old blankets used as batting. Just as long as they are durable. I made one using up some fleece I had, the dogs loved laying their head on the fleece. As far as size - just so they fit in the kennels, so varied sizes. They quilts are washed frequently so they must be durable and well - stitched.