Assembly insights
The basic kumiko grid teaches precision cutting and assembly at small scales. Each intersection requires careful mortise-and-tenon work, training the eye and hand for more complex patterns. This pattern is where many artisans begin their kumiko journey before advancing to Asa-no-ha, Sakura, and other decorative infill motifs.
Historical context
The kumiko grid (組子格子) is the structural foundation for all kumiko patterns. Thin strips of hinoki or other fine-grained wood are joined at half-lap or small mortise intersections to create a lattice that receives decorative infill. The grid alone appears in simple shoji and room dividers; more elaborate ranma panels build complex patterns on top of this base. Kumiko work flourished during the Edo period as interior architecture became increasingly refined.
Construction steps
- Rip thin strips to uniform width using a kumiko plane; typical thickness is 3–5 mm.
- Cut half-lap joints or small mortises at each grid intersection using a fine dozuki saw.
- Assemble the grid on a flat surface; check for squareness with a small engineer's square.
- Fit infill pieces into the grid if adding a decorative pattern on top.
- Install the completed panel in the shoji or ranma frame without glue.
Where to see this joint in Japan
- Traditional shoji screens — Temples, inns, and machiya throughout Japan
- Kumiko specialty studios — Fukui prefecture — Taniho Kogei and similar workshops
Variations
Grid density varies from coarse (for large panels) to fine (for ranma transoms). Some grids use through-mortises; others use half-laps only. The same grid supports Asa-no-ha, Sakura, Goma, Benten Kikko, and Shippo infill patterns.
Applications
- Shoji screens
- Room dividers
- Decorative panels
Tools required
- Kumiko plane
- Fine dozuki saw
- Square
- Marking gauge