The 18oz vintage denim is woven in the famed Shinya Mills in Japan, one that specializes in vintage style fabric. This denim is a loose weave woven slowly with low tension on old shuttle looms. It starts off a bit crunchier and hairier than other Iron Heart denim, but will fade fast as it opens up. As the name suggests, these 18oz denim will fade to a vintage appeal. The 634 cut is based off the 1966 Levi's 501, a straight fit with a medium rise and slight taper at the bottom.