I always thought I knew my feet pretty well. I’m a size 11.5 (US) and have a weird big toe, and I have broken my little toe on both feet several times, so I thought I knew the shape.
What I didn’t know is that my left foot is longer than my right, and my right foot is wider than my left. I also didn’t know that my right heel flattens out considerably when I stand, and that it has a higher arch than my left by several millimeters.
I found this out while visiting a store in New York called TM:RW. I was there to meet with Syntilay CEO Ben Weiss to discuss the company’s 3D-printed shoe and to have my foot scanned for a pair to test alongside our executive producer, Bridget Carey.
3D printing is bringing some much-needed individualism to the shoe industry. We can now have shoes that are custom-fitted to our feet — without spending outrageous prices to do it. I’ve tried the entire process from start to finish, and I’m here to tell you that the future has arrived, and it’s bringing back that bespoke cobbled feel.
Customized foot scanning is so easy
The scanning itself was done without any big fuss. Despite having a pedicure done beforehand, I wasn’t required to take off my socks.
I stood in the spot shown on the machine, and several small cameras positioned around my feet took pictures from all angles, generating an accurate 3D model of both feet simultaneously. I checked the model against my actual be-socked foot and could see the lumps and bumps that made up my unique limb were indeed where they were supposed to be. I can attest that this scan was a true likeness of my appendage. A quick email with my shipping details and the scan data was sent to Germany, where the shoes were to be made. More on that later.
It’s worth noting that this scan, while showing all the curves and edges, isn’t as detailed as a scan you would get at an orthopedic office. It uses photogrammetry to create a 3D model using pictures, unlike an orthopedic scan, which uses IR light to build your scan.
You don’t even need to go into a store like TM:RW to make the scan; you can use a web app through Zellerfeld, the company that physically makes the shoe. Zellerfeld also securely holds your scan data to allow you to buy more shoes from it with the same configuration. There is also a feedback form to make any tweaks to your next shoes if the first pair isn’t quite right.
Design and manufacturing decoupled
With this new 3D-printed manufacturing model, design and production no longer need to go hand in hand. One company, Zellerfeld, has developed the 3D printing material and techniques to produce the shoes, while many companies can design shoes for Zellerfeld to print. Massive companies such as Nike and Justin Bieber’s brand, Skylrk, already make shoes with Zellerfeld, but smaller startups have room to grow in this environment, too.
Syntilay is a fashion shoe brand focused on the emerging short-form creator space. The company has been using AI to help design its shoes, which it says saves both time and money when rapidly prototyping.
«We used AI to create very precise concept artwork instead of going to the sketch board right away and having to do countless sketch revisions,” said Weiss. Syntilay uses “a pattern and texture generator … to cycle through countless iterations of how they should look,” which allowed the team to come to a final design.
The outcome is a shoe called the Luminez sneaker, which, according to Weiss, is 95% AI-created and 100% 3D printed. It has the feel of a futuristic shoe, with organic lines and a pattern mesh across the surface that highlights how these shoes are a single piece. No stitching or hint of multiple materials is visible — just a continuous wave of lines in motion. I think the black ones are pretty cool looking, though the red ones are even better.
Weiss explained that, while shoe deals are possible for sports personalities, the infrastructure isn’t there for TikTok or YouTube stars, some of whom have millions of followers, often more than athletes. By working with Zellerfeld and these creators, Syntilay is helping develop shoes tailored to them that can be produced in small but impactful batches.
Even smaller than Syntilay is TV and YouTube producer David Tobin. Tobin has been working with Joel Telling to create the 3D Printing Nerd YouTube channel for nearly a decade. Like me, Tobin has a passion for 3D printing. He also loves skateboarding and wanted to create footwear that melded his two passions.
His design, the D7, is a more traditional-looking shoe, while still retaining that all-in-one, seamless look that only 3D printing can achieve. It’s a board shoe, so it has a lot of grip on the bottom and lattice work on the front that allows for breathability.
Syntilay and Tobin have two completely different business goals and design styles, but both can find resolution via 3D printing. When the designer of the shoe is decoupled from the manufacturer, we can have a lot more variation, and because there is no heavy machinery, nothing needs to be made in batches of 10,000 to achieve profitability.
Using the scanned foot data that Syntilay has allows us to go one step further. The exterior design of the shoe can be as outrageous as you like because the inside of the shoe is custom fitted. It’s the best of all worlds.
Small batch manufacturing is the way forward
Zellerfeld is the 3D printing company of choice for the shoe industry. Nike is the biggest name you know, but dozens of smaller companies use its production facilities in Germany and the new large-scale factory in Texas to create a plethora of shoe designs.
Bespoke design is possible because Zellerfeld’s 3D printers aren’t constrained by the processes of traditional shoe factories. Zellerfeld instead prints shoes in one piece, eliminating concerns such as loose stitching and the like.
Zellerfeld uses bespoke FDM 3D printers that are similar to those found on Amazon but on a larger scale. They use nozzles from E3D, like most of the best 3D printers, and they print the same materials, like flexible TPU that you may use, albeit with a few twists.
The material Zellerfeld uses is a modified version of the TPU that you can buy for a regular 3D printer. It’s called Zellerfoam, and as the name suggests, it has a foamy texture rather than the rubbery one you get with standard TPU. It’s a lot softer but can be printed with different infill and wall patterns to produce different compression rates as needed.
After the print is finished, the shoes are checked for any errors and washed to remove any of the support materials produced during manufacturing. (The washability of these shoes is another high point in my eyes, as they don’t contain any glues or materials that may not play well with detergent.)
Finally, the shoes are checked again and sent on their way with a pair of socks as a little gift. The entire process took around 35 days from the day I got my foot scanned to receiving the Luminez sneakers. That’s longer than I would have liked, and even the shorter time of 25 days for my colleague’s shoes to arrive felt a little long.
Zellerfeld is working on reducing that time by expanding its factories out of Germany and into Texas. This US expansion comes with more printers, and shorter delivery times will bring the time it takes to get your shoes on your feet down considerably.
Like walking on a cloud
Wearing the shoes for a month or so felt both futuristic and pedestrian. It was interesting to have a pair of shoes that are 3D printed by robots and 95% created by AI, but it also felt mundane because they felt good, like a high-end pair of shoes should. I spent the entire month of November on a transatlantic trip, stopping in England, Spain, Madeira and the Bahamas, testing the Luminez on every terrain I could.
My left foot immediately felt the customized fit. The instep, toe box dimensions and the heel size seemed to hug my left foot exactly as it should. It was fully supported in a way that I don’t think I’ve ever had a shoe do before.
I wasn’t so lucky with the right shoe. The heel felt loose, and my foot slipped slightly inside. I think the scan captured my heel flatter than normal because I lean my weight on that side when I stand. This gave the right shoe a larger heel, which is a problem when in motion. I will definitely change it before I get another pair.
It’s also worth noting that none of these shoes have laces; they are either all sliders or slip-ons, even the boots. When you’re engaging in strenuous activity, laces help keep your shoe where it’s supposed to be. Without them, it’s natural for your shoes to slip around a little.
The Luminez from Syntilay feels like a premium slip-on shoe with futuristic design and materials. I know that $195 is a lot of money, but it’s not hugely unreasonable for custom-fitted shoes that feel like they are giving your feet a great big hug. My wife’s Hoka trainers were $150 and are considered high-end sneakers, despite the soles already coming apart in less than six months. By comparison, 3D-printed shoes aren’t that far off, pricewise.
Can you 3D print shoes at home?
If the material used and the printers are similar to those you might have at home, you might think it would be easy to 3D print your own homemade shoe. It turns out, it’s both easy and difficult: easy in that the files exist and look amazing, and difficult in that it takes a lot of patience, the right materials and some luck to get a working pair of your own.
I recently reviewed Bambu Lab’s latest flagship, the H2D, and used it to print a pair. I started with a design from Cloudberry — a prolific 3D printed shoe designer who gives their designs away for free — called the Bubbleberry and set to work.
Turns out, when you have giant clown feet, even the H2D isn’t big enough to print both shoes together. Cloudberry provided guidance on how to scale the shoe to fit the standard generic shoe sizes used in most countries. If I had access to my foot scans from Syntilay, I could have used those to help me measure the right size, but that would have been extremely complicated.
Printing them turned out to be a frustrating process. My first two attempts failed because I tried to print using TPU as the support material. They ended up binding together so tightly that I couldn’t remove them without damaging the shoe. Even after I got a full shoe I was fairly happy with, it still had a lot of defects. The layers hadn’t bonded well, leading to splits in different places. And the whole shoe felt more rigid and uncomfortable.
Once the first shoe was finished, I researched ways to make the next one better. I needed to keep the TPU warm as it was printing. I also needed to adjust the PLA supports to better handle the interface between materials. My second shoe was a lot better and felt like one I’d be happy to wear for long periods. I did add an insole from Walmart to the finished shoe, though that is the only part that wasn’t 3D printed.
I spent the next week wearing them, and while they did work, they started to chafe around my heel and where the top of my foot rubbed against the entrance. The clever infill used by the designer made them feel like moon boots from the ’90s — so bouncy and light.
So how much did it cost? Quite a bit, actually. While TPU is relatively inexpensive, you need to use the correct type. I used Bambu Lab 90a TPU as it’s softer than some other types, making it more comfortable and less likely to create a sole that slips on hard surfaces. One box of TPU cost me $35, and it ended up taking about two rolls, as well as a roll of PLA ($18) for the support. In reality, though, I should have reprinted the first shoe to make a better quality version, so the real cost is closer to three rolls of TPU and one of PLA, totaling $133.
If everything had gone perfectly, which never happens, I could have printed my own shoes for about $95, including the insoles. That doesn’t include any labor hours, print hours or electricity, though, all of which add up. The Syntilay shoes cost $195 delivered, which is more expensive, but with that price comes quality assurance and a professional finish you just can’t get with at-home materials.
Zellerfeld’s Zellerfoam is not commercially available, and while it is a TPU variant, it isn’t the same as the stuff you buy at Microcenter. It’s lighter while still being tough, and it would likely need some special settings to make it work on your standard Bambu Lab or Prusa machine. It’s also completely recyclable, so unlike most shoes, these Zellerfoam shoes can be sent back, chopped up and, with a little new TPU, can be remade into new shoes.
Recently, Siraya Tech — a leading manufacturer of 3D printing resin — released its Flex TPU Air, which feels very similar to the Zellerfoam these sneakers are made of. I would like to make a pair of shoes using that material to see if it works better than the harder TPU I used.
Even if I could match the material perfectly, I still wouldn’t be able to reproduce what makes a 3D printed shoe special in my eyes: the ability to custom-fit a commercial shoe to anyone’s exact foot. That requires more technology and know-how than is currently available at home.
We are so close to the future
The mechanization of shoemaking in the 1850s marked a turning point in how we view clothing manufacturing. By standardizing the size and shape of everyone’s shoes, they could be produced in the thousands and made inexpensive to boot. This sort of mass production killed the customization that a cobbler provided but allowed everyone to afford well-made footwear that could last longer than the leather wraps that came before.
Not much has changed in the last 175 years. We have new designs and materials, but we still use the same rough estimate of our foot based on the length, regardless of the safety concerns. No care is taken for variation in length, width or height, and outside orthopedics, no real care on how your foot truly fits inside the shoe.
Right in front of us is a bespoke future. One where anyone can get made-to-order and made-to-fit apparel that can be delivered to our homes or picked up in stores for the same price as the destructive fast fashion we have now. We aren’t quite there — 35 days is just too long for one pair of shoes — but it’s within reaching distance.
We are on the verge of a change for the better, and if we can convince these companies to give credits for returned shoes for recycling, we can help reduce the terrible waste that fast fashion produces. If we can get the print time down to an Amazon Prime-style 2 to 5 days, including shipping, I think we could see a revolution.
Custom-fitted 3D-printed shoes certainly aren’t a return to pre-1850s cobblers who made shoes from scratch. However, the prospect of individual comfort, of a bespoke product built just for you, is an exciting one.
