The iconic sock monkeys made from red-heeled socks, known today as the "Rockford Red Heel", emerged at the earliest in 1932, the year the Nelson Knitting Company added the trademark red heel to its product. In 1932, advertising executive Howard Monk came up with an idea to change the heel of the brown sock from white to red. The red heeled sock was marketed as "de-tec-tip". Nelson Knitting added the red heel "De-Tec-Tip" to assure its customers that they were buying "original Rockfords" as opposed to the generic "Rockfords". This red heel gave the monkeys their distinctive mouth and during the Great Depression, American crafters first made sock monkeys out of worn-out Rockford Red Heel Socks.