- Sumi Ink & Saddle-Core Chemistry: Crafted from 1.5mm full vegetable-tanned horsehide dyed with 1,400-year-old botanical Nara sumi ink over an aniline-dyed saddle core base.
- Archival 1950s Silhouette: Inspired by rare mid-century catalog store-brand work jackets, featuring transposed lowered patch pockets ("down pockets") for ergonomic hand-warming.
- Multi-Dimensional Patina Kinetics: Frictional wear gradually abrades the matte black carbon soot surface, exposing a deep amber-brown saddle undertone over years of oxidation and wear.
- Dual-Lined Chassis: Insulated through the torso with lightweight, vapor-permeable Wool Etamine and finished with high-density friction-resistant smooth nylon sleeves for effortless layering.
- Heritage Construction Details: Built with solid metal custom branded tuck buttons, double box-pleated front plackets with bar-tack stitching, and a period-correct lumbar cinch-back (martingale).
- MADE IN JAPAN
Nara Sumi Chemistry and Saddle-Core Tanning Mechanics
The SHB-163 Type II Jean Jacket represents a masterclass in materials engineering, merging traditional Japanese ink-making with heavy-gauge vegetable horsehide tanning. The foundational pigment relies on Nara sumi ink, an artisanal craft originating in the Nara prefecture over 1,400 years ago. Produced through the incomplete combustion of plant-derived rapeseed, sesame, and paulownia oils, the resulting carbon soot is hand-kneaded with natural collagen glues into solid ink sticks.
Because botanical soot particles are substantially coarser than modern synthetic dyes, binding them deeply into a dense vegetable-tanned horsehide collagen matrix presents extreme technical hurdles. To engineer the distinct saddle-core structure, premium Scandinavian and Oceanic horsehides undergo an intensive vegetable tannin soak followed by an aniline dye saturation designed slightly darker than traditional saddle tan. Master dyers then apply the Nara sumi ink across the grain and suede surfaces with micro-calibrated viscosity control—preventing black pigment from bleeding into the core while eliminating premature surface flaking. The hide is then subjected to specialized mechanical milling (mulling), flexing tight collagen bundles to mobilize the grain and yield a surprisingly relaxed hand-feel out of the box.
Archival Silhouette and Structural Architecture
Rather than reproducing generic mid-century denim jackets, Y'2 Leather drew structural inspiration from rare 1950s commercial store-brand outerwear produced by catalog icons such as Montgomery Ward, Hercules, and Sears. The standard Type II layout—defined by horizontal mid-torso chest pockets—is re-architected by transposing the dual patch pockets down to the lower hemline. This lowered "down pocket" configuration creates natural hand-warmer utility and improved gear storage.
The front placket maintains traditional double box-pleating secured with rectangular bar-tack stitching, allowing controlled mechanical expansion across the chest when flexing forward. Across the lower rear waist, a period-correct buckled cinch-back (martingale) allows waist tuning while retaining authentic mid-century store-brand aesthetics. The internal chassis features a Wool Etamine lining through the torso—a sweet-twisted, coarsely woven woolen cloth that captures thermal air pockets without adding excess weight—paired with friction-resistant smooth nylon sleeve linings for effortless layering over heavy flannels and knitwear.
Patina Kinetics and Chromatic Evolution
The sumi-dyed saddle-core horsehide exhibits one of the most distinctive aging progressions in high-end leather outerwear. Initially displaying a matte, light-absorbing jet-black finish, the micro-layers of sumi pigment slowly abrade along high-friction ridges—such as sleeve honeycombs, elbow apexes, cuff edges, and pleat folds.
Unlike conventional chemical "tea-core" leathers that break down rapidly into bright yellowish-tan undertones, the SHB-163 slowly uncovers a rich, dark saddle foundation. As the exposed hide oxidizes under natural sunlight and absorbs natural body oils, it creates a multi-dimensional chromatic contrast between jet-black carbon soot and glowing amber-brown undertones. Light applications of animal oils or conditioning waxes can be used to darken abraded fibers, while ongoing frictional heat restores a deep, mirror-like leather burnish over time.