cut knit fabric pieces 9 inches by 4 inches. Folded and sewed together (9"x 2" results) and turned right side out. Inserted two pieces of foam in each curler. Sewed the edge and sewed a "dam" to keep the foam in place. Installed the snaps. When I roll my hair, I interlock the curlers as I go. I find that having them all chained together makes it more comfortable to sleep.