Inspired by American sportswear from before the 1950s—an era prior to the widespread use of synthetic materials—this sweatshirt features a flat, planar construction achieved through direct cutting, similar to the Lot.601 Tee Shirt, and incorporates functional details such as front and back V-gussets at the neckline, which were once common but later omitted due to advances in technology and cost efficiency; the jersey fabric is knitted slowly on a traditional loopwheel machine, one of the few still in operation today in Wakayama, Japan. Originally introduced during the Taisho period, this rare machine produces only about one meter per hour. The result is a fabric with gentle irregularity and a rich, airy texture. By using USA cotton, the fabric achieves a dry hand and uniquely vintage feel. Each color—YAKUSUGI, SAKURA, MUD DYED BROWN, and USUZUMI—is carefully garment-dyed by hand, making every piece one of a kind. T.T’s iconic LOT.603 Sweat Shirt is garment-dyed using kakishibu (persimmon tannin), a traditional Japanese dye. In addition, a unique ink-marbling pattern, resembling the rings of a tree, is individually transferred from the surface of water. This marbling technique called Suminagashi, originating from a pastime of the Heian period, involves dripping ink slowly at the center of a water surface. Over time, irregular concentric rings resembling tree rings form. Each garment is floated on this inked surface and the pattern is transferred. Due to subtle movements in the air and water, no two patterns are ever the same. By entrusting the final touch to nature, the design captures not only the uncontrollable beauty of natural forces, but also the passage of time as each ring forms.