We guard our stocks of Shinki Horsebutt jealously. We expended the majority of this extremely rare, Cordovan-tanned leather last year. A few details:
The leather is pit tanned using a fully vegetable-based process at Shinki Tannery in Himeji, Japan. Due to high connective tissue content, the leather is nonporous, extremely durable, and uniquely resistant to creasing. It contains the hard “shell,” underlayer, making these wallets nearly impossible to destroy.