How to make a wooden kumiko jig.
Every kumiko pattern is dozens — sometimes hundreds — of little pieces, each with precise bevels pared into its ends so they lock together cleanly.1 The tool that makes those angles repeatable is a guide block: a simple wooden jig that holds your chisel at exactly the right angle while you pare. Here's how to make one, drawn from Matt Kenney's The Art of Kumiko and cited throughout.
New here? Start with the Tools & Materials guide first.
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I'd rather you make one than buy one.
Kumiko can feel locked away — the know-how sits in a handful of workshops, and the tools are hard to source. I don't want to be another closed door. So every guide on this site is free to read, and the STL files for my jigs are free to download and print. Grab them, run them off on any printer, and start cutting.
I make and sell physical jigs too — but as a convenience, never a gate. If a free guide and a free file are all you ever take from me, that's a win. Below I'll show you how to make one in wood, where a wood jig lets you down, and — honestly — where a printed one earns its keep.
It holds the angle, so you don't have to.
Many kumiko pieces have a double bevel pared into each end so they seat into a corner or form a new one. Those angles have to be exact — a degree off and the pattern gapes or the pieces fall apart. Rather than eyeball each cut, you pare against a block whose face is already at the correct angle; the block guides the chisel and every piece comes out identical.1
Two blocks cover the square patterns.
The angles that come up again and again in square-grid patterns are 45°, 22.5° and 67.5° — and you'll want two 67.5° faces. So make two blocks: one carrying a 45° and a 67.5° guide surface, the other a 22.5° and a 67.5°.2 Triangular patterns like asa-no-ha (hemp-leaf) use a 60°-based grid instead, but the block is made exactly the same way — just to different angles.
What you'll need
A dense, straight-grained hardwood (maple is ideal) makes the most durable, accurate block.3 The rest is layout and edge tools you likely already own.
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Hard-maple blockFind on Amazon
About 1⅞″ thick × 2⅜″ wide × 9″ long per block — the exact size isn't critical, but dense hardwood holds the angle.3
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Combination squareFind on Amazon
For the 45° layout line and checking the guide face stays square to the block.4
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Sliding bevel gaugeFind on Amazon
Set it from the protractor to carry the 22.5° and 67.5° angles onto the block.4
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Large full-circle protractorFind on Amazon
The wide-spaced degree lines of a big 360° protractor lay out odd angles far more accurately than a school half-circle.4
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Low-angle block planeFind on Amazon
The one tool that makes or breaks the jig — it cleans the guide face (end grain) dead-flat and true.6
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Thick CA glue & a fine sawFind on Amazon
CA glue assembles the tiny stop parts fast; a fine dōzuki or backsaw handles the cuts.7
Making the guide block, step by step.
Following Matt Kenney's method in The Art of Kumiko.1 A bandsaw speeds the rough cuts, but a handsaw works too — the accuracy all comes from the block plane at the end.
Groove the block
Start from a clean hardwood block (~1⅞″ × 2⅜″ × 9″). Cut a groove about ¼″ deep × ¾″ wide along each face — this is the track your stop will ride in later. A dado set cuts it flat-bottomed and square in one pass; a router or repeated saw kerfs also work.3
Lay out the guide angles
For the 45° face, draw the line with a combination square. For 22.5° and 67.5°, mark the angle on a scrap of MDF with a large full-circle protractor, set a sliding bevel to it, then transfer that line to the block.4
Why the big protractor: its degree marks are spaced far apart, so the 22.5°/67.5° lines are genuinely accurate — a small half-circle protractor can't hold that tolerance.4
Rough-cut the guide surface
Saw away the waste just outside your layout line, leaving a hair of material to clean up. It doesn't need to be pretty or perfectly on the line yet — the next step does the precision.5
Plane the guide surface true
Pare the face down to the line with a sharp low-angle block plane (you're planing end grain, so a keen edge matters). As you go, check two things: the face is square to the block's edges, and the angle is dead-on — at least across the top half of the face, where the chisel actually rides.6
This is the whole game. Every kumiko piece inherits this surface's accuracy, so take your time and keep the plane sharp.6
Add a stop for repeatable lengths
Drill two pilot holes in each groove, then build a small sliding stop from two side strips and a couple of short middle strips (glued up with thick CA so the slot stays centred). Now you can dial one piece to length, lock the stop, and pare the rest to the exact same size.7
For the frame, not just the pieces.
The guide block shapes the infill pieces. For the frame around them, Kenney builds a dedicated tablesaw crosscut sled with a small finger-joint jig fixed to its fence — that's what keeps every opening uniform and square, and the pin-to-kerf distance sets your border width.8 If you'd rather work by hand, Des King's Book 3 details a set of angled cutting jigs (45°, 60°, 15° and jaguchi) that hold each strip while you saw the joint — a classic alternative.9
Where a wood jig lets you down.
I'd never talk you out of making one — it's a genuinely good way to understand the craft. But a wood guide block has real limits, and you should know them going in:
- The guide face is end grain, and end grain wears. Every chisel stroke leans on it; over time the face dents and the angle quietly drifts.
- Getting the angle dead-on by hand is hard. A fraction of a degree at the block becomes a visible gap once it's multiplied across every piece in a panel.
- Wood moves with the seasons. A block that was true in a dry winter shop can be a touch off by a humid summer.
- One block is one angle and one width. New stock size or a different pattern angle means cutting a whole new block.
- Softwood won't hold up. You really need dense hardwood and a keen plane to get a face that lasts — a skill hurdle of its own.
What a 3D-printed jig fixes.
None of this makes the wood jig wrong — it makes it a trade-off. A printed jig trades a little soul for a lot of repeatability:
- The angle is baked into the model. Every print is the exact same geometry — no hand-planing your way to a perfect 67.5°.
- It doesn't move with the weather. PLA and PETG hold their shape season to season.
- The faces don't dent like end grain. And if one ever wears out, you reprint it for pennies instead of remaking a block.
- You can build in features that are fiddly in wood. Captive sliding stops, registration marks, a clamp-down cap — easy to model, painful to cut by hand.
Where this comes from.
The build on this page follows the guide-block method in Matt Kenney's The Art of Kumiko (Blue Hills Press), with a nod to the hand-tool cutting jigs in Des King's Shoji and Kumiko Design — Book 3. Both are worth owning:
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The Art of KumikoFind on Amazon
The source for this guide — makes the guide blocks, sled and finger-joint jigs, then ten infill patterns and decorative panels.
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Shoji and Kumiko Design — Book 3Find on Amazon
Advanced projects with an appendix of the classic 45°, 60°, 15° and jaguchi cutting jigs.
References:
- Guide blocks hold the chisel at the correct angle while paring the double-bevels on pattern-piece ends. — Matt Kenney, The Art of Kumiko, "Use guide blocks for accurate angles," p. 22.
- The common angles in square frames are 45°, 22.5° and 67.5°; make two blocks (45°+67.5° and 22.5°+67.5°). — Kenney, pp. 22–23.
- Guide-block dimensions ≈ 1⅞″ thick × 2⅜″ wide × 9″ long, with a ¼″-deep × ¾″-wide groove; exact size isn't critical. — Kenney, p. 22 (Guide Blocks diagram).
- Lay out 45° with a combination square, and 22.5°/67.5° with a sliding bevel set from a large full-circle protractor — its wider-spaced marks are far more accurate than a small half-circle. — Kenney, "A big protractor makes angles easy," p. 23.
- Rough-cut the guide surface (bandsaw or handsaw), leaving waste outside the layout line. — Kenney, pp. 22–23.
- Clean the guide surface with a sharp block plane, keeping it square to the block's edges and dead-on in angle where the chisel rides. — Kenney, "Clean up the guide surfaces," p. 24.
- Add a stop so every piece is cut to the exact same length — dial one in, set the stop, cut the rest. — Kenney, "Add a stop," p. 25.
- A dedicated tablesaw sled with a finger-joint jig on the fence yields uniform, square frame openings; the pin-to-kerf distance sets the border width. — Kenney, "Jigs simplify kumiko," pp. 17–21.
- A classic hand-tool alternative: angled kumiko cutting jigs (45°, 60°, 15° and jaguchi). — Des King, Shoji and Kumiko Design — Book 3, Appendix A (Jigs).