urushibased

Urushibased is an adjective used to describe materials, finishes, or products that are based on urushi lacquer, the traditional natural resin obtained from the lacquer tree (Toxicodendron vernicifluum). In practice, urushi-based coatings act as the binder and primary film-forming component in the finished item, often combining natural lacquer with pigments, metals, or additives.

Composition and chemistry: Urushi lacquer is a waterborne resin that cures through enzymatic oxidation and polymerization when exposed to air, forming a hard, flexible film. Traditional formulations rely on multiple thin coats (nuri) applied with a brush, with sanding between coats. Modern urushi-based products may incorporate additives or be processed as composites, but maintain the characteristic glossy, durable surface.

Techniques and process: Application involves controlled layering, drying, and finishing. Makie, a famous urushi technique, adds powder decorations after certain layers, protected by subsequent coats. Urushi-based finishes are valued for adhesion to wood, resilience to impact, and high gloss.

Properties: Hardness, toughness, scratch resistance, and water resistance can be optimized by layer count and post-processing. The final film is typically clear to amber-toned, with a warm luster that deepens with age.

Applications: Traditional lacquerware, including boxes, bowls, and furniture, as well as contemporary art, musical instruments, and consumer products, utilize urushi-based coatings or adhesives.

Safety: Urushiol in raw urushi lacquer can cause allergic contact dermatitis in some people. Proper handling, ventilation, gloves, and skin protection are advised.

History and context: Urushi-based finishes have a long history in East Asia, especially Japan, China, and Korea, dating back centuries. Today, they are used in heritage crafts and modern design, often blending traditional technique with new materials.