This is a strip of cork fabric cut parallel to the selvage edge for making straps.
Cork has a slight stretch in one direction. When making straps it is better to cut the length parallel to the selvage to avoid that bit of stretch. It will help your straps to wear better over time. They are also less likely to twist while sewing.
Small pieces are 12"wide by 48" long
Medium pieces are 24"wide by 48"long
*A small piece makes four 3" strips (3/4" wide finished strap) OR three 4" strips (1"wide finished strap). All straps end up 48" long.