Oak leather

(Bot.) the mycelium of a fungus which forms leatherlike patches in the fissures of oak wood.

See also: Oak

Webster's Revised Unabridged Dictionary, published 1913 by G. & C. Merriam Co.
References in periodicals archive ?
Rob uses only Hermann Oak leather, known for being the oldest tannery in the U.S.
The blades are hardened to 58 Rockwell, and each cross-draw sheath is handmade from Hermann Oak Leather. The cross-draw style promotes a more comfortable carry and allows for easier removal.
Crafted of Hermann Oak leather, saddle skirting steerhide with a proprietary treatment that Bachman is understandably reluctant to share, the test holster's edging, stitching and tooling were impeccable.
The Relic's design is a fusion of Hermann Oak Leather and a Boltaron polymer shell.
Holster makers recognize the name Hermann Oak Leather as the best provided for producing quality holsters and that is exactly what Rick uses.
While TR uses mostly rough-out, Rick only works with Herman Oak leather, smooth side out, and finishes it with a marvelous color and texture.
The Herman Oak leather is just the right weight, and Rick set the snap strap at the correct length to allow "condition one" carry.
Rick scrimps on nothing and uses Hermann Oak leather exclusively.
You'll find that the leather used on every Mernickle holster is top-of-the-line, flawless, vegetable tanned, tooling hides from Hermann Oak Leather, the Rolls Royce of leather.