I bought these to use when potty training, but my child didn't really like them and hardly wore them. However, the fabric has become a little fuzzy. The inside is terry cloth, and it's thick, which should help prevent soiling the sheets, although I can't guarantee it. These are used items, so please understand that before purchasing. Would you like to buy them at a low price? The size is M. I'm not certain, but I think the size was right when my child was around 90 cm tall.