I have a gridded very light weight flannel (almost like a combed cotton) on mine that I believe I bought from Keepsakes Quilting about 5 years ago. I love the grid although I really don't know why because it isn't necessary. Individual blocks stay up without any problem. When you start sewing the rows together for the quilt, it can get too heavy to stay up by itself so I use pins which go through the insulation board without any problem. I also can clean the threads away with a lint roller.