I finished this cool roll-top backpack a few weeks ago for my lady. It’s constructed of 1000 denier Cordura on the outside and lined with a 14 oz vinyl coated polyester on the inside. It was my first time working with closed cell foam, so there’s 1/2” thick foam in the shoulder straps and in a back panel. The loops on the bottom rear of the pack were a special request to hold her yoga mat. It came out very nicely and is seeing daily use. I’m currently working on a prototype of a porteur bag using some of the same ideas and materials. Will post on here when it’s finished!