Any 56"+ width fabric works, up to 4 per yard.
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 fat quarter size makes it easy to fold or roll up and transport for play on the go. 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