Put Your Confidence In The Strength Of Duro Sacks. For standard supermarket bags, Duro Bag offers customers an in-depth line of products in a variety of sizes. Duro Bag Sacks are available plain or with customized printing. 1/6 size is standard supermarket bag, 1/7 and 1/8 sizes, slightly shorter. Plain or custom printed in kraft or white paper. Seasonal prints available.