Kumiko is a Japanese woodworking technique of creating intricate patterns using multiple pieces of wood. Each piece is pressure-fit with bevels to lock them together. Today, I'm going to show you how to make the beautiful and simple Asanoha pattern.
Like all kumiko, you need pieces for the frame. For the asanoha pattern, we’ll also need diagonals, the pieces we’ll call the hinges, and the pieces that lock the hinges.
And of course, you'll need kumiko paring jigs to make the angles and a sharp plane or chisel. I use a cheap thumb plane from the big box store; it works great after a tune-up.
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Step 1: Milling Kumiko Strips & Frame Joinery
All Kumiko patterns require long, thin strips to work with. I normally work with pieces that are 1/8" wide by 1/2" thick, by about 2 or 3 feet. You can either mill your own strips, or purchase them through a kit online. If you're interested in learning more about milling Kumiko strips, check out my Instructable here.
Once I have enough strips, I'll cut the joinery that makes Kumiko work: the cross-laps. I do this by taping a number of strips together and cutting them on a table saw sled fitted with a jig that functions like a box joint jig.
The distance between cross-laps isn't incredibly important for a practice piece like this, as long as the distance between the cross-laps stays consistent. But if you're going for a certain number of cells inside a frame, for example, you will want to plan what that distance is. And in general it's really difficult to make the inner pieces on frames that have cells less than 1.5" x 1.5".
Step 2: Assembling the Frame
Once the joinery is cut into the strips, I'll separate frame pieces, being sure to leave at least 1/2" on the outside of each cross-lap at the end for strength.
I need six pieces with cross-laps for a basic frame. To join them, I use a dab of glue at each joint and connect the frame on a piece of MDF so it will stay flat. This doesn't need clamps at all, so I just set it aside to dry, and once it has dried for about a half hour I can go on to the next step.
Step 3: Fitting the Diagonals
The diagonals will stretch across each cell in an 'X' pattern. To start, I'll mark a rough length — something at least 1/4" longer than the final piece will be — and separate enough diagonals for the frame.
I put a diagonal piece into the 45 degree jig until it protrudes just a bit. I slide the stop to meet it and tighten it down. Referencing the jig's angled face, I cut a bevel on one side.
Then I flip and repeat for the other side to create this 90 degree angle at the end. Once I have a good fit, I’ll repeat with the other three.
Note: I normally will make extras of each part. Fitting the pieces inside of the frame is a trial and error process, so it pays to have a few extra of each piece. And if I have a piece that doesn't quite fit, I'll try it into one of the other cells. The likelihood that all cells are exactly the same size is very low, so my piece might work. But if all else fails, I'll just scrap that piece and use an extra one, making sure I solve for the error first.
Step 4: The Hinges
Fitting the Hinges
For the hinges, I switch to the 22.5°/67.5° degree jig. I'll separate enough pieces from the strips for 16 hinges (plus a couple extra).
First, I cut a 22.5° bevel on both sides of one end to form a 45° angle. I rinse and repeat for all 16 hinges before moving on to the other side.
For the opposite end of the hinge, I mark the rough length of the hinge — a strong 1/8" longer than it needs to be — and carefully cut a 67.5° bevel on two of the hinges using the 67.5° side of the jig, then test them. I want the two hinges to meet without any gaps.
If the hinges are still a little too long, I'll carefully bump the stop block forward and take a tiny cut before checking again. Once I have the right size where the pieces meet perfectly, I'll cut the 67.5° bevel on the remaining fourteen pieces to catch them up to this point.
Cutting the Lock Pockets
Now's the fun part. I am going to cut the 67.5° side two-thirds down the thickness of the Kumiko piece to create a pocket where the lock will fit.
I adjust the stop block slightly until it looks like 2/3 of the bevel is sticking out. Then I'll pare carefully on two hinges.
Once I have a good fit on these two hinges, I use the already set-up jig to cut the remaining fourteen.
Step 5: The Lock Pieces
Finally, for the 8 lock pieces I start by cutting a 90° angle on one end just like I did with the diagonals. Then I mark the lock’s rough length and place it back in the jig with the other end out.
Since this is a critical cut, I’m going to take my time and take thin cuts until I get a good tension fit. Too much tension and it will bend the frame, while too little tension will mean it won’t hold together.
Repeat for all of the locks, slide them into place, and I have my final asanoha pattern.
Note: Kumiko is designed to hold together without gluing the pieces in, but whether you do is totally up to you. I like to glue my pieces so they stay in place over the long-term. I will generally glue pieces in as I go along, but you can also try to disassemble the pattern once every piece is fit, keeping the pieces in order, and glue them all at once.
Step 6: Conclusion: Sanding & Finishing
Traditionally, Kumiko isn't sanded or finished. Instead, Japanese Kumiko craftspeople will use a Japanese hand plane to level out the pattern and create a glossy finish. I, however, only have the ability to sand them to level the pattern, so that's what I do. I'll put a piece of sandpaper on my workbench and lightly run the pattern over the paper until it's flat.
I generally do not finish my Kumiko patterns — it's incredibly difficult to get into the nooks and crannies between the pieces. If you're so obliged to finish them, spraying or dipping your patterns is probably the best bet.
But that's all there is to making a stunning Kumiko. If you've made this pattern, I'd love to hear about it. DM me on Instagram!