Any 56"+ width fabric works.
I recommend sewing a solid knit backing material on the other side of this play mat to make for a nice, solid surface that is WASHABLE! The larger size can double as a comfy and fun blanket! Email me for additional sizes and colors at hello@campclever.co. Check out the whole play mat collection here: https://www.spoonflower.com/collections/636775-play-mats-by-campclever