During World War II, to comply with wartime rationing requirements, Levi Strauss & Co. simplified the features of the 501. To save metal, fabric and thread for the war effort, the cinch back was removed, along with the watch pocket rivets and crotch rivets. What's more, the trademark arcuate stitching design was no longer sewn on, but instead painted on by hand. Dye rationing meant that the heavy-duty 10oz red ID line shrink to fit xx denim used in 1944 was a softer shade of indigo, offset by the one sided Caital E red tab introduced in 1936. The jean was riveted in a mixture of plain and stamped metal, and the LS&Co. logo no longer appeared on the fly buttons. Instead, the waistband button was engraved with a symbol of peace in the form of a laurel leaf. The laurel leaf is widely used to symbolize the triumph of the human spirit.