RACC Make|Learn|Build 2021-22

Thanks to a Make|Learn|Build! grant from the Oregon Regional Arts and Culture Council (RACC), I have been able to spend time working with some current 3D imaging and CAD software to see where and how these technologies might be suited in a custom shoe making workflow.

Scanning

Structure Sensor Pro

Part of the money I received was used to purchase a Structure Sensor Pro. This scanner is based on infrared light, similar to the Kinect and other structured light scanners. Structure Sensor Pro requires an iOS device to run, so I also had to buy an iPad. With this handheld scanning setup, I acquired scans of 5 pairs of feet. I also scanned some of the lasts used for this project and lasts used to make shoes previously.

Scans of feet must be manipulated in some way to make them fit into the digital last models. Most feet are scanned on a flat surface, but most lasts are not flat. A lift of the heel is needed and some lifting of the toes as well. This already requires some assumptions about how a foot might behave when manipulated in this way. Even though I could manipulate the scan of the foot enough to make it fit inside the bounds of the last, the scan data does not provide enough information to know if this is actually possible for the given foot, or if it would be a comfortable and pleasant fit.

CAD

McNeel Rhinocerous Logo

My original plan was to use a customized CAD program offered by the German last manufacturer Spenle. They offer this on their website, but I could not get them to sell or license a copy to me or work with me in any way on it. I purchased a copy of Rhinoceros 7, a very capable CAD program that is also well represented in the footwear world. This also meant I had to learn CAD for real in order to make a usable model of a last to send out for production.

Lasts

I wanted to adjust digital models of lasts based on scans of feet for each person scanned and then have those carved to see if I could begin the custom shoe fitting process from a better starting point than if I just ordered by length and width. I did indeed do this, but only for one individual. Because I did not have access to the library of lasts from the last manufacturers, I had to buy scans of lasts and build my own models. I modified the physical lasts to fit and then compared the scan of the modified last with the scan of the feet to visualize feet in a last that fits. I also very significantly modified a model and sent it out for carving.

Shoes and Fit

For each person trial shoes, or fitting shoes, were made and the lasts adjusted as needed before the final shoes were made. The real test of whether the last fits is whether the shoe fits. Since I have some experience fitting feet, lasts and shoes, I thought it would be interesting to see how this fit is visualized.

In practical terms scanning feet using a handheld scanner is pretty fussy. It can take quite some time and the results vary in accuracy. It is difficult to capture the feet from every perspective in order to obtain a complete 3D scan. I used the same scanner to scan lasts, but the edge detection is not good enough to get clearly defined edges especially around the feather line.

The visualization of the feet and lasts is not intuitive. While I think most people would imagine that a foot fits inside a shoe, and thus a last, and in seeing these two things together, one might expect to see just that – a foot inside a shoe. In real life, the foot really does go in the shoe. On the computer the foot protrudes in all sorts of way that would lead an untrained observer to assume a particular combination of foot and last is not a fitting one when in fact it is.

Consider the “hand in glove.” A hand goes in a glove and if you scan a hand and a glove, it’s extremely unlikely that these two shapes will line up on screen as well as they fit in the physical world. This is a limitation of computer modeling of elastic forms. The real world is elastic in ways that the computer is not. This is not to say that the computer can’t model elasticity at all, only that the wild variation of mobility and flexibility in human beings can’t be captured by a surface scan and modeled using only that. It’s important to set realistic expectations and know the limitations of the medium.

Below are images of feet and lasts and the shoes made on those lasts. Can you tell which of these fit to the satisfaction of the wearer?

In Progress

These images are of works in progress. The fitting shoes have been made and the results are good, but the final shoes have not yet been made.

Many Kinds of Fit

To state the obvious, the size alone does not determine the fit. The fit really depends on the shoe. Not just the shape of the shoe, but what the shoe is made of and how it is put together. Shoes of the same size but different materials and/or different construction techniques will not fit the same. One person may also have many fit preferences. Maybe sometimes they want a loose fit and other times a tight fit. Most people prefer a range of fits. Shoes are made for many types of uses and occasions – ritual and otherwise. For some occasions the fit is as socially constructed as the look. None of this is readily visible even in a really good 3D scan of a person’s foot.

Visualizing the Fit

With the examples I’ve provided here, it is possible to see how the digital images of feet and lasts can be combined to visualize the fit. With some insight and knowledge of anatomy and biomechanics, feet and shoes, it’s possible to make sense of these images and discern the ways in which a particular fit might be displayed. The difference between a shoe that fits really well and one not that great can be very small, and possibly not even something one could see in the images.

Facial recognition software can do a decent job of identifying landmarks of a face, but it can’t tell you anything about the personality behind the face. Likewise, 3D images of feet on their own are not enough. In many ways the blueprint, or Harris Mat print, provide more useful information than a surface scan of a foot. To get a complete picture, you have to know more about the feet, and shoe that was or will be made and more importantly, the person who will wear it.

In the process of gathering all of the information needed to successfully make custom shoes, 3D imaging of feet can play a part. The bigger role for 3D imaging, in my opinion, is the ability to capture and reproduce lasts that have been modified to a wearer’s preference. To make adjustments to digital last models and to be able to compare these changes is valuable indeed. For capturing images of feet, infrared scanners might be serviceable enough, but a more accurate scanner is needed for lasts.

Orthopedic Boots

My first pair of 100% orthopedic shoes. I’m not an orthopedic shoemaker, but many of the shoemakers I studied from in the Netherlands are. Why call these orthopedic? I’ve made lots of shoes for people who wear “orthotic inserts.” These boots different. They are a textbook case of how to handle hallux valgus – your basic big bunion and also dealing with foot and ankle instability. The blueprint shows how different the feet are.

On the right foot, there is a significant bunion on the first metatarsal joint (big toe). There is also a bunionette on the little toe ball joint of the right foot. She has had some plantar fasciitis, pain and tenderness on the bottom of the foot. Not a lot of mobility in MT1, the big toe.

The left foot has no such issues, but due to a stroke, my client lost some facility with her left leg creating balance issues and instability with the left ankle and foot. Looking at the print of the left foot, those issues are not visible. The left foot is also a full size longer than the right, and two widths narrower in the standard sense. Her issues have nothing to do with her left foot per se, and yet everything to do with it. Getting to know the client, seeing and feeling the feet first hand is an essential part of making custom shoes. In this regard, the knowledge I got from in person contact is critical to the success of working with her.

For an orthopedic shoemaker, dealing with hallux valgus is really no big deal. Basic beginner stuff. Their daily work is typically with clients that have much more complicated conditions. I have an understanding of these issues, but since I’m not a trained orthopedic specialist. I referred her to one. She said “No.” She really wanted me to make them. I told her that I would take a crack at it, no guarantees.

What to do? I referred to my copy of “Orthopedisch maatschoeisel in de medische praktijk” (1991), by Dr. Klaas Postema. This hand me down from my colleague Rene van den Berg, was the standard textbook that he and many of the shoemakers I met in the Netherlands studied in school. I read through that and Dr. Postema’s latest book, “Pedorthic footwear – assessment and treatment” published (in English!) in 2018. I also thought back on all the discussions I’ve had and shoes I’ve seen at Mischa Bergshoeff’s shop in Gouda. You can look at his work and see how amazing it is and have no idea of what sort of feet go in those shoes.

There is a prescription for hallux valgus, a sort of shoemaking recipe, in the books. Depending on the mobility of the foot, you can squeeze it a bit around the tarsals and that will actually straighten out the bend in MT1 slightly. This should ease the stress of toe-off in walking and possibly give more flex to MT1. Extra room is needed for the bunion and bunionette, but the foot will slip forward to fill that space unless you keep it firmly in the rear 2/3 of the shoe. It’s important to keep the rearfoot firm and secure. It’s a tight fit, but should not be uncomfortably tight. To help keep the ankle and foot in position, the upper is about a hand’s width above the ankles (malleolus). There is a firm heel counter and a rocker bar to assist in toe-off. I made a padded contoured footbed liner with metatarsal bump to helps restore the transverse arch.

Like any recipe, you need to season to taste. Most people don’t want to go to “orthopedic specialists” because they are most famous for making ugly shoes and boots. The difficulty of clinically handling the many foot pathologies orthopedic shoemakers encounter is already extreme. On top of making the most appropriate shoes possible, people also demand they look great. Sometimes there is a real disconnect between the shape and functionality of the client’s feet and what the client wants to see when they look at the shoes. As a custom shoemaker, it’s my job to balance those things. For an orthopedic shoe, it’s no different, just more difficult.

These shoes are EU 39-9(L) and 38-10(R). I wanted to use a Vibram Gumlite unit sole because it’s cushy to walk on and a good all-weather material. Vibram, however, typically only makes huge soles available to the distributors in the US like only men with giant feet need their soles. It’s very hard to get the right size unit sole for a custom shoe, but once the shoe is size 41 or less, you really have to start hacking to make it fit. When I made the trial shoes, I simply made sure the sole covered the shoe. As you can see from the tread pattern, this is not nice. Would anyone even notice? I noticed and I didn’t like it. At the very least, the shoes have to satisfy me.

I had to shorten these to get a passable agreement of the heel and forefoot. If you look closely, you’ll see the word “Gumlite” is gone from the final version. I made a straight cut and then sanded a 1 cm skive for the 39 and 1.5 cm skive for the 38. Previously, I have cut these along the curve of the heel and made an overlap. This time I wanted to try something new. The cut along the curve of the heel looks more finished, but the increased contact area and a transition before the edge of the heel on the straight cut and skive should keep the heel more solidly bonded, at least in theory.

Who doesn’t  love a hidden feature? There is one for the wearer and one for shoemakers. For the wearer, there is an embossed inside lace stay. This allows me to use more rust colored thread for not-totally-gratuitous ornamental stitching to sew it in. The embossed stays can only be seen when the shoes are open.

When they are open, look at the back of those speedhooks! Have you ever seen such a clean finish? Thanks many times over to Mischa for this method of setting speed hooks. I want to thank all the shoemakers who helped reach the point where I am able to make shoes like these, and thanks to Dr. Postema. I couldn’t have done it without you.

Green and Brown Medium Hiker

It’s been a few years since I made myself a hiking boot. (I gave the last pair to a lifelong friend with the same size feet.) It’s been even longer since I first got the pig suede I wanted to use for them. I really liked the sage green color when I saw it at the Footwear Materials show here in Portland. With some time on my hands during the pandemic, I had no more excuses to put this off.

The pig suede quarters are made by Wolverine – the tannery and brand perhaps best known for the Caterpillar (CAT) brand boots in a striking yellow suede. They treat their leather with a water resisting silicone. It’s flexible and seemed like a good choice for a hiking boot shaft.

The vamp and outside counter are Italian cordovan. The boots are hand sewn using double-stitch welted construction. The hidden feature is a basalt fiber footplate between the leather insole and leather midsole. It’s intended to put a little spring in my step. Basalt fiber is much safer to work with than carbon fiber, but the strength and function is the same. The footplate is quite stiff in the heel/shank section where the fabric is more compressed and flexible in the forefoot where the fabric is thinner.

A not so hidden, but maybe not so obvious feature, is the lack of back seams on either the upper quarters or the liner quarters. Why not? Finally, it is finished with a Vibram Montagna outsole.

Cordovan Oxfords

These cordovan full brogue oxfords are made with Horween Color 8 cordovan uppers sewn with rust colored A&E Tex 70 thread. They are lined with undyed vegetable tanned calf. The soles are J.R. Rendenbach covered with Vibram cat’s paw. The leather heels are topped with Vibram heel caps. It’s all put together with welted construction using a hand dyed welt and beige hand sewing threads attaching the welt to the leather sole.

These oxfords feature a few interesting details worth pointing out.

Why rubber over leather? Leather is a good material for both soles and heels because it shapes to the last and foot. Good soling leather is tough and flexible, but it has its limitations. Leather does not insulate as well as rubber, which can mean cold feet on cold pavement. The rubber has better grip on a wider variety of surfaces and helps reduce the amount of water the sole is exposed to when the ground is wet. The rubber heel cap also grips a wide range of surfaces and is very hard-wearing. Both the sole cover and heel cap are easily replaced when worn. It makes for a good all-purpose, all-weather shoe. There’s no one shoe to rule them all and it’s nice to have the right shoe for the job if you can. You might choose to wear these instead of your leather-only soles in certain circumstances.

Most, if not all, cordovan is top finished, not drum dyed. When cut, you can see the color only slightly penetrates the top surface. The undyed original color, (typically a light brown) is then visible. That cross section is usually not shown on the shoe upper, but is often hidden by skiving and folding the edges.

Cordovan can sometimes be difficult to fold, and the fact that it is finished flesh-side out makes skiving problematic for the integrity of the material. I have found the thickness of Horween’s cordovan to be highly variable – from 1.2mm to 2.2mm in the same piece! I used the thick parts of the material for the quarters, and rather than skive and fold, I rounded and finished the exposed cross section. With the right treatment, it appears as if it were skived and folded – which only actually occurs where the top of the outside counter captures the backs of the quarters. (See above.)

What even is “cordovan?” It’s *both* a special piece of horse leather *and* a color. (I’ve written about this before.) Horween actually calls this reddish brown color “Color 8.” Maybe this is because in the 1930 edition of “A Dictionary of Color” by Maerz and Paul, Cordovan is listed as a color on page 39, Plate 8, Color Sample H8.

I don’t often dye the welts I use for welted construction, but I needed to figure out how to match the color when dying the blunt cut undyed top line. The “cordovan” colored dye was just brown, lacking even a hint of red. What matched most closely for me was using “burgundy” dye and then rubbing it with an uncolored oil and wax finish. This darkened the burgundy considerably and made the color I wanted.

Leaving aside for the moment all the problems with color correction, lighting and digital displays, you can still get a good idea of the color matching. It’s very difficult to distinguish the part of the topline that I dyed from the rest of the material below the stitching. The dyed and finished welt looks a bit more red because the undyed welt is much lighter in color than the undyed cordovan. I expect the welt to darken in time, but I think it’s a good match to start.

Cordovan is an interesting and unusual leather. The special attention required to the material thickness, skiving, folding and finishing make it an additional challenge to work with.

Color 8 Cordovan Derby Boots

The client requesting these boots wanted a roomy fit in the front, but also needed room for an orthotic insert that takes a fair amount of room in the back. I really like the quality of this particular orthotic. It is better than most I have seen.

At the last minute, he requested a bit of ornamentation. I’m of two minds on ornamentation. On the one hand, some ornamentation is just fine. On the other, many times the ornamentation, in the form of broguing, degrades the integrity of material on the seams right where the strength is needed most and they must be sewn twice to make up for it. The broguing on this boot is not on any seam. The line of sewing that borders it, however, does sew in the undyed part of the liner. Rather than having a strip underlay the broguing, the quarter facings from the liner seam forward are lined with cordovan as can be seen behind the speed hooks above right.

On the red cordovan boot I made before this pair, I used the color of the liner for contrast, which also matched the stitching. On these “Color 8” cordovan boots, the rust colored stitching serendipitously matches the undyed cross-section of the leather made by the hole punches.

These boots were made using double-stitch construction. The welt is sewn straight into the insole then down to the sole. With the reflection of the bright finish and deep colors, it’s difficult to get a true feel of the color and texture. I’ve included this last photograph on the carpet to help put the color in context.

Red Cordovan Derby Boots

These custom boots, made for winter use, feature a basalt fiber shank which covers the entire heel and arch area, giving very solid support. I have recently started making shanks and reinforcing components using basalt fiber because it’s much safer to work with than carbon fiber.

I assembled this pair using welted construction. The welt is hand stitched the to the leather outsole which is covered by a thin layer of Vibram soling so they could spend more time on wet surfaces. The upper is vegetable tanned shell cordovan.

Lis Royal – Rocinante – Cordovan Derby

cordovan brown derby
cordovan brown derby

I was given a sample cordovan shell from a tannery in Argentina called Lis Royal. The line of cordovan leather is called Rocinante and the color is “Dark Brown.” It is a lovely dark brown. I’ve written about cordovan before, but this sample was my first opportunity to make a pair of cordovan shoes for myself. The representative for the tannery told me that the horses in Argentina are kind of small, so I should expect the cordovan shell to be on the small side as well. Indeed it was a very tight fit to get a complete shoe pattern on a single shell. To do so, I had to forego any skiving allowance on the quarters.

This is on an Alvin 24″x36″ cutting mat. I think you can get the idea that this is not a lot of material. No mistakes in cutting or marking allowed!

The leather arrived with a very glossy classic cordovan finish. This makes it challenging to sew because there is so much glare it’s hard to see. I used a contrasting rust colored thread and vegetable tanned liner embossed with a leaf pattern.

The embossing is quite deep, but the cordovan is also ~2mm thick, so there was no visible trace of the embossing from the outside, as you can see above.

I have heard from others who have worked with it, that cordovan is very stretchy. In lasting you can pull and pull and keep pulling. I did not find this to be the case for this shell. I was actually stressing about the back height as I felt that my pattern came up short in length from the heel seat to the top line. I was hoping to have some stretch there, but it definitely didn’t want to.  Ok, to be fair this is the first time I made a pair of shoes on this particular last and the volume of the heel seemed to be a bit bigger than I expected. I’ll take responsibility for a pattern error on that. There was very little lasting allowance. In the end, it fit, but it was a close shave.

I have used cordovan from a few other tanneries and usually the finish goes to matte quite quickly after wetting and lasting. The Rocinante from Lis Royal held its finish pretty well. I have questions about the nature of the finish. The top side of cordovan is in fact the flesh side of the skin. Creating the finished “top grain” means shaving away everything until you get just the callus that is cordovan. Lis Royal did a really good job as it still remained quite smooth when wet and pulled. With a sample size of one, it’s hard to tell what was a property of this particular shell and what was part of their process. In any case, we’re off to a good start! I’m looking forward to seeing how this beautiful material performs in wear testing.

This pair of cordovan derby shoes is sewn with an English welt to a J.R. Rendenbach vegetable tanned leather sole. They have stacked leather heels capped with a Vibram heel lift. The stitching on the welt is dark brown and the welt is dyed dark brown. The welt thread color and dye treatment were not my first choice, but that’s a different story. Note that this last has a bit of a bulldog toe. On the subtle side, but a bulldog toe nonetheless. The bulldog toe shape, which rises and then drops as you look at the profile from the side was very popular in the years 1910 – 1920.

Two tone cordovan wingtips

I made these two tone cordovan wingtips for a client who really wanted dress shoes, but he has wider than average feet, and much wider than average heels. He had never found a dress shoe that fit.

The uppers feature quite a bit of broguing. Broguing is often done with a tool that has a combination of punches at fixed distances for consistent hole spacing. Brogue punches have one big hole punch and two or four little hole punches on either side. If you punch it freehand with individual large and small hole punches as I did, you can make whatever combination you want.

I made assembled this pair using welted construction and hand stitched the welt to the leather outsole. The upper is vegetable tanned shell cordovan.

Last making with paroir slideshow

T-Strap Nouveau Revisited

I don’t usually take clients with a deadline because so many things can happen to delay the making of the final shoes. I don’t feel comfortable putting work out there that I can’t feel proud of, so I’d rather be late than not meet my basic standards for the look and the quality. Nonetheless, I took this job for a client who had a special event because she knew exactly what she wanted and she said she wanted the shoes whether or not I made them in time for her event. I still put a lot of pressure on myself to get them done in time. I encountered an unprecedented number of technical difficulties. Shoemaking is a process of on-going problem solving, but to figure it all out in time was very difficult. I started over completely 3 times. In the end, this pair was a new speed record for me. From first meeting to final shoes in 2 months! (Don’t get any big ideas out there…)

This t-strap features a single seam on the upper which is done with a “feather stitch.” The design itself is a modification of a model I previously made from a design in a book I have called “Women’s Shoes in America, 1795-1930.” The client who requested this design collects embroidery. Since I first tried this stitch, I’ve wanted to find more ways to use this beautiful embroidery stitch on a structural seam. It seems that machine embroidery these days is almost always ornamental, and good luck finding an industrial machine that will do an structural embroidery stitch with three needle positions on leather!

I tested this out before going sewing on the final leather. When it came time, however, my Bernina would not sew this consistently at all. I tried small test pieces which would go ok, only to have it totally stall, error out and bind up when sewing on the uppers proper. When I first gave up on trying to make this embroidered seam happen, I sewed the whole thing on my straight-stich postbed, but I was really haunted by the fact that these were for an event dedicated to embroidery. (Maybe it would have been better if she had not told me the details of her event.)

In the end, I switched to a slightly lighter weight tumbled Italian leather that I’d never used before. It was the only leather that behaved halfway decently with the embroidered stitching. The tumbling made it wrinkly and kind of matte in appearance, which I did not like for this purpose, but this was before lasting. I knew it would smooth out after lasting, but honestly didn’t know exactly how it would come out. You can still see a bit of the tumbling effect, especially in the cut out sections which were not pulled so significantly.

Like my previous client, she was unable to wear a heel as high as the original design featured, so I made this low heel version just for her. The closure uses a button post (aka a “mini Sam Brown button”). There was no hole in the strap yet when I took this picture because punching the hole is really a one shot deal. Using a button, you can’t make adjustments like you would be able to with laces, or a buckle. To make a perfect fit, you have to check the stretch of the strap and mark it while the client is wearing the shoes.

The upper is Italian vegetable tanned calf, the liner is a combination of rose colored vegetable tanned goat and undyed vegetable tanned cow. The sole is Rendenbach with Vibram heel cap.