The fabric is cotton covered in basketballs, and the lining is food safe ripstop nylon. The sandwich bag is made the exact same way, just large enough to accomodate almost any size bread.
The snackbag is about 4 1/2"x6" (12x15cm), and has a zipper closure. The sandwich bag is 7" square (18cm) and also closes with a zipper.The lining can be wiped out with a damp cloth, or you can machine wash the bag when needed.
For more bags, both singles and sets, check my snack and sandwich bags section http://www.etsy.com/shop/OriginalsbyLauren?section_id=6983603