Making a Kimekomi Ornament with a Hot Foam Cutter: What Worked, What Didn’t, and What I Learned
I finally pulled out one of those high-density foam shapes I’ve been avoiding for years and tried cutting it with a hot foam cutter. Spoiler alert: it was a game-changer (but not without a few surprises).
In this post, I’m walking you through my process of making a kimekomi ornament using a hot foam cutter, sharing everything that worked, what I’d do differently next time, and what I learned along the way. If you’ve ever struggled with hard polystyrene foam or wondered whether one of those hot cutters is worth it, this one’s for you.
In case you’re new here, you might be wondering…
What is Kimekomi?
Kimekomi is a traditional Japanese craft technique where fabric is tucked into grooves carved into a molded shape to make dolls and other decorative ornaments. Traditional artisans make wood composite casts for their creations. I use polystyrene foam, which is very affordable and readily available at most craft supply stores, to make things like Christmas ornaments and Easter eggs.
Normally, I prefer low-density foam because it’s easy to cut with a regular craft knife. But a long time ago, I bought a batch of high-density foam shapes that turned out to be way too tough for my usual tools. So they’ve just been hanging out in storage… until now!
Trying the Hot Foam Cutter
For this project, I used a Clean Cut foam cutter by FloraCraft (not sponsored).
The cutter heats up in a couple of minutes, and I made sure to open a window and wear a protective mask.
Here’s what I learned:
The heat is strongest along the full length of the tool, not just the tip. Once I figured that out, it made cutting grooves easier and more consistent.
The melted grooves are wider than what I’m used to. My usual craft knife leaves a very narrow groove, but the hot cutter leaves one that’s about 2mm wide. That changes how the fabric behaves when tucked.
Dense foam is brittle. The melted edges became hard and sometimes flaked off, especially at corners. I used a rotary tool to smooth those edges, and had to be careful not to chip off chunks of foam.
Tucking Fabric: A Bit Tricky, But Doable
Since the foam didn’t have any give, I couldn’t rely on it to grip the fabric like I usually do. I had to use glue inside the grooves before tucking, which is actually more in line with traditional kimekomi.
A few other things I learned the hard way:
Tuck all your fabric before the glue fully dries. I waited a couple of days between sections, and that made the second section much harder to work with.
Deeper grooves would’ve helped. I didn’t cut mine deep enough, which made tucking the fabric a bit of a struggle.
Be careful when tucking around corners. It chipped easily, so I had to be super gentle.
Finishing Touches
Once the fabric was in, I glued down some quilt batting for a softer finish and added one of my favorite Japanese fabrics over top. Then I glued down some wide braided cord over the seams, which finally justified the stash of cord I’ve held onto for over a decade (take that, storage guilt 😄).
At the top, I added a bead cap and gold cord for hanging. I even used hot glue for the bead cap, which is something I don’t usually do, but it worked great!
One More for Good Measure
After finishing the first ornament, I felt inspired to try a second one using what I’d just learned. I used a lantern-shaped foam form and went with deeper grooves this time. Cutting straight lines with the hot cutter was surprisingly easy. I just laid the tool against a straight edge and let it melt its way in.
I made sure to tuck all the fabric before the glue dried, and I was so much happier with how it turned out. Definitely a win!
Final Thoughts
If you’ve been on the fence about trying a hot foam cutter, I hope this helped you decide. It’s not perfect for every project, but it saved my hands a ton of effort and made cutting dense foam so much more manageable.
If you're curious to see the full process, you can watch the video here for a step-by-step look at how it all came together.
