I have found pet screen at Wal Mart (black only) and made 3 bags from one roll. I use the "Screen Play" by Nancy Ota pattern. I also use the 1" web you can buy at JA's for the handles rather than using the cut off part of the screen. I leave that on the piece of screen and get a deeper bag for shopping. The pattern is for sizes S-XL. I usually make size M for my shopping bag and have made an XL for sewing stuff (25" W by 18" tall finished). I use the heavy duty cardboard for the bottom (triple thick like appliances come in) and read once using #7 plastic cross-stitch canvas can be used to give extra strenghth in the bottom also.
I have brought home colored screen from Zoe's Trunk in AZ when I visit a friend there.