Envirosax Organic Linen Bird Bag. Linen may be the oldest textile material in the world. Its history goes back many thousands of years. Fragments of straw, seeds, fibers and yarns, which date back to about 8000 B.C. have been found in Swiss lake dwellings. Linen was also used in the Mediterranean in the pre-Christian age and was even sometimes used as currency in ancient Egypt. 100% linen. Each pouch is small enough to fit into a handbag or the glove compartment of a car. No more excuses for leaving your reusable bags at home!