These bags are made from poly/plastic woven feed bags. They are multi-purpose and reusable and very tough. I sew them with heavy gauge thread. The bags have a rectangular bottom with a seam up each corner. The bags are unlined. I use them for travel but especially for shopping. http://www.facebook.com/media/set/?set=a.10150466017564004.387898.785969003&type=3 DO NOT click "Buy it Now". My paypal account is [email protected] Thanks!