From muntins to a craft
JAANUS defines kumiko first as muntins: the light, non-structural strips set inside the frame of a door, window or sliding shouji screen, with translucent paper pasted over the back to make the shouji. It also uses the word for lattice strips in gable pediments and in the screens that divide the inner sanctuary of a shrine or temple. The decorative craft grew from that joinery for fittings — tategu, JAANUS's term for removable doors, screens and shutters. In Okawa, in Fukuoka Prefecture, kumiko is a Governor-designated traditional handicraft; its producers' account describes about 300 years of history, more than 200 patterns — asa-no-ha (hemp leaf), gomagara (sesame), yae-zakura (cherry blossom) among them — and pieces assembled without nails.
How a panel is built
| Term | What it is | Source |
|---|---|---|
| Kumiko 組子 | Lattice strips or muntins; also the craft | JAANUS |
| Jigumi | The framework or grid the pattern sits in | Okawa account |
| Mitsukude | The method of assembling three pieces into the framework | Okawa account |
| Kudegiri and warikomi | Sawing the notches, then refining them with a narrow plane | Okawa account |
| Tsukeko | A thin frame between the jigumi and the outer frame | Okawa account |
| Kumiki | The pattern pieces fitted into the jigumi | Okawa account |
| Shouji 障子 | A screen of frame and muntins, paper on the back | JAANUS |
| Tategu 建具 | Removable doors, screens and shutters | JAANUS |
Kanji are given for the JAANUS terms; the English Okawa account gives its terms in romanisation only.
The Okawa account describes the work in order. Wood — chiefly Japanese cypress, also cedar, hiba and magnolia, chosen for colour — is dried for at least five years and cut to 2 mm or thinner. Notches are sawn and refined with a narrow plane, and the jigumi framework is assembled; the tsukeko frame sits between it and the outer frame and strengthens the whole. The kumiki are then made with planes, saws and a marking blade and fitted into the jigumi one by one, checking how tightly each holds, the finer parts first. The producers say a deviation as small as a sheet of paper's thickness affects the result. In the simplest grids the crossings are half-lapped: each strip is notched to half its depth so the two sit flush — the joint used in the lattice panel project.
Starting out, and thin strips
- Consistent strips first. Every crossing depends on strips of one thickness and depth. Plane them to size — see hand planes — or rip them on the table saw only as its manual allows.
- Ripping thin stock. DEWALT's manual calls ripping small pieces unsafe: rip a larger piece and take the part from it. It specifies a push stick when there is 2–6 in between fence and blade, and its narrow-rip auxiliary fence and a push block at 2 in or less, and never holding the cut-off side between blade and fence. See table saw safety.
- Notches by hand. A fine saw and a narrow chisel cut half-lap notches. See Japanese saws and chisels.
- The wider tradition. Kumiko is one branch of Japanese joinery; for the joints themselves see choosing a wood joint.
Starting kumiko
- Straight, even-grained, dry wood
- Strips planed or ripped to one thickness and depth
- Thin parts ripped from a wider board, never freehand
- A grid laid out from one reference
- Notches cut to half the strip's depth, tested on scrap
- Pattern pieces fitted snugly, finest first
Sources
The craft process is the Okawa producers' own account, published by JTCO; its claims of extreme precision are given as theirs. Terms are JAANUS's or the Okawa account's. Strip-ripping rules are DEWALT's for its saw; your saw's manual controls.
- 1.
kumiko 組子 (glossary entry). Japanese Architecture and Art Net Users System (JAANUS).
Used for: Kumiko as the non-structural muntins set within the stiles of doors and windows and the thin members that fill the frame of a shouji, and as lattice strips in gable pediments, sliding screens and the screens dividing a shrine's or temple's inner sanctuary.
- 2.
shouji 障子 (glossary entry). Japanese Architecture and Art Net Users System (JAANUS).
Used for: Shouji as sliding, hanging or fixed partitions, translucent paper pasted over the back of frame and muntins, and muntin arrangements from closely spaced to widely spaced.
- 3.
tategu 建具 (glossary entry). Japanese Architecture and Art Net Users System (JAANUS).
Used for: Tategu as the generic term for removable screens, doors and shutters.
- 4.
Okawa Kumiko: Okawa Kumiko Wood Joinery. Japanese Traditional Culture Promotion & Development Organization (JTCO), credited to the Society for the Promotion of Okawa Traditional Craft.
Used for: Okawa kumiko as a Governor-designated traditional handicraft of Fukuoka Prefecture with about 300 years of history; pieces assembled without nails; more than 200 patterns, among them asa-no-ha (hemp leaf), gomagara (sesame) and yae-zakura (cherry blossom); wood dried at least five years and cut to 2 mm or thinner; Japanese cypress chiefly, also cedar, hiba and magnolia; the jigumi framework built from three pieces (mitsukude) after sawn notches (kudegiri) refined with a narrow plane (warikomi); the tsukeko frame between jigumi and outer frame; kumiki made with planes, saws and a marking blade (kehiki) and fitted snugly, the finer parts first; deviation of a sheet of paper's thickness affecting the result; kumiko on the balustrades of Horyu-ji's Golden Hall.
- 5.
DWE7491 10" (254 mm) Job Site Table Saw, Instruction Manual. DEWALT.
Used for: Ripping small pieces being unsafe — rip a larger piece to obtain the part instead; a push stick with 2–6 in between fence and blade, and the narrow-rip auxiliary fence and push block at 2 in or less; never holding the cut-off side between blade and fence.
About this reference
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