The Ump Shorts are made from a dry cotton blend sourced from the USA and Australia, is made by spinning organic cotton into nep yarn in Japan and then weaving it. A high level of skill is required to create a natural, rustic ("neppy") surface and to control the strength and weakness of the nep. Normally, it is mercerized to give it a clean surface, but in order to bring out the roughness of organic cotton, Jackman does not mercerize it but rather applies a degreasing and washing process to give it a dry, natural texture. Based on classic baseball umpire pants, a large pocket is placed from the waist to the hips while the waist features an elasticated drawstring with belt loops.