Much like selvedge denim woven on vintage shuttle looms, our Japanese loopwheel fabrics are steeped in history and tradition — but what makes them so special?


How Does Loopwheel Knitting Work?


Sometimes referred to as “tubular” or “circular” knitting, loopwheeling is a very different process from most common textile production methods. A traditional loom produces long lengths of flat fabric, which are then rolled up, ready to be cut and sewn into garments. The loopwheeling process, however, knits yarn around a cylinder to create a three-dimensional, tubular piece of fabric. While a loom weaves horizontally, loopwheel machines are suspended vertically, with multiple units belt-driven from a central motor. Unlike a modern loom, where the tension can be adjusted to produce tighter or looser weaves, loopwheel machines rely entirely on gravity to stack layer upon layer of cotton, gradually building up a tube of fabric.



The History of Loopwheeling


The original design for the loopwheel machine was patented by Italian inventor Giuseppe Negra in 1926. Before the advent of modern, fully automated machinery, his invention offered an efficient method for producing garments such as T-shirts (which, at the time, were worn mainly as undershirts) and sweatshirts. The tubular fabric formed a complete body, requiring less cutting and stitching to finish each piece. For the next few decades, loopwheel cloth became the primary method used to construct sporting apparel and military undergarments — items that would ultimately spark the T-shirt style revolution.


In the 1950s, many American textile manufacturers began upgrading to faster knitting machines, increasing production efficiency tenfold. During the Allied occupation of post-war Japan, many of these so-called antiquated machines — including shuttle looms and loopwheelers — were imported to help rebuild Japan’s textile industry and economy.

There are now only two places in the world where authentic loopwheel cloth is produced: the Merz B. Schwanen factory in Germany and the Kanekichi Industries facilities in Wakayama Prefecture, Japan.


The loopwheel fabric used to construct Iron Heart garments is sourced from the latter, home to the majority of the world’s remaining loopwheel machines—known in Japan as tsuri-ami-ki machines. Today, around 400 of these machines remain in Japan, with fewer than half in full working order; the rest are used as donor machines for parts and repairs. Since no new machines or replacement components have been manufactured since the 1970s, most working loopwheelers have been carefully maintained for 50 to 85 years. In theory, this means the production of loopwheel cloth could be finite, as the remaining machines may eventually become impossible to repair.