A Foundation of Fossilized Algae
The exceptional durability of Wajima-nuri (輪島塗), a traditional lacquerware from Japan's Noto Peninsula, has a surprising geological origin. The secret lies in a powdered undercoat material called jinoko (地の粉), which translates to "earth powder". This is earth; it is high-quality diatomaceous earth, a sedimentary rock composed of the fossilized remains of single-celled algae called diatoms. This material is found locally and is a feature of the Wajima-nuri technique.
The process of creating Wajima-nuri is extensive, sometimes involving over 124 distinct steps performed by specialized artisans. An important stage is the application of multiple undercoats of raw urushi lacquer mixed with the powdered jinoko. The microscopic, porous structures of the diatom fossils absorb the lacquer, creating a reinforced matrix that significantly increases the hardness and longevity of the finished object. This unique substrate makes the lacquerware remarkably resistant to damage. This technique of using a diatomaceous earth undercoat is a primary reason Wajima-nuri pieces are known to last for over 100 years.