The IH-634S is Iron Heart's signature jean in their world famous 21oz fabric, and given an overdye in sulfur black dye. This jean features super heavy 21oz denim that is so soft it feels much lighter because of it's loose weave. The break-in of these jeans is easy, despite the weight and heft of the denim. The 634 cut is based off the 1966 Levi's 501, a straight fit with a medium rise and slight taper at the bottom. These jeans are sanforized, and the dying process takes out any additional shrinking. Known to produce some amazing fades, the 21oz overdyed black fabric is one of the most popular Iron Heart has to offer.