The bags need to be transparent so the cashier can read the produce label, lightweight because produce is usually weighed, and washable and sturdy enough for multiple uses.

These bags are suited for storing most fruits and vegetables, but the mesh bag is unable to retain the moisture needed to keep lettuce from wilting.

Construction instructions:

The cloth produce bag is made from sheer curtain fabric for transparent fruit and vegetable viewing and light weight properties. Alternative materials could be tulle, nylon netting, and hosiery material. A rectangular section of fabric is cut and then folded in the middle (diagram 1 and 2 — for all diagram images, please see the Image Gallery). Start with a rectangular piece 12" wide by 24" long before folding.

The fold forms the bottom of the bag. The sides are sewn together with a French seam (diagram 3). For a French seam, sew the wrong sides of the fabric together with a 1/4" seam allowance. Turn the bag inside out, with the right sides together, and sew another seam, this time with a 1/2" seam allowance. This traps the raw edges of the sheer fabric and completes the seam nicely. The top of the bag is finished off with a traditional hem (diagram 5). To close the bag, a light weight ribbon is attached with reinforcement to the bag (diagram 6).

User Image - Blocked by "Display Image" Settings. Click to show.

article from http://www.motherearthnews.com