Nature is infinitely creative when it comes to shapes and structures. In my design work, I especially love finding ways to use unusual natural forms in a functional way. With this in mind, I thought it would be fun challenge to create a sandal inspired by the shape of an octopus, where the tentacles became straps wrapping around my foot and leg.
As a maker of many kinds of wearables, constructing my own shoes has always seemed like the Holy Grail of clothing self reliance, fascinating, but somehow intimidating. I know a lot of people who make their own clothes, but almost no one who has tried their hand as an amateur cobbler. While serious shoemaking does require a lot of specialized tools and materials, making your own sandals is really relatively straightforward, and it's a great place to start learning about footwear construction.
I also found that the act of taking raw leather and transforming it into a pair of functional, and wholly unique, sandals was immensely satisfying. The basic structure of this type of shoe is really fairly simple and once you understand the concept, the design possibilities are endless... though I'm not sure why you would want anything other than an octopus on your foot.
In this Instructable I'll show you how to use your own foot to create patterns for the sole and straps of a leather sandal, and how to finish and assemble your leather components for a sturdy and polished final product.
All beach photos by: audreyObscura
Step 1: What You Need
- Adjustable V-gouge
- Edge beveler
- Burnishing tool
- Skiving tool
- Stitching groover
- Diamond stitching chisel - I used one that creates holes 1/8" apart, it was useful to have one that has switchable heads with different numbers of prongs so you can go around curves etc.
- Rotary hole punch
- Manual punch
- Small and large seeder stamps
- Exacto knife and extra blades
- Thick waxed thread and a leather needle
- Quartz slab or other very hard surface and a softer poundo board to put over it
- Octopus stamp to mark the sole of your sandal (optional)
- Leather lace cutter for making the straps (optional)
- Mini anvil for pounding in rivets (optional)
Leather Finishing Supplies:
- Gum Tragacanth for burnishing
- Black Pro Waterstain, or a leather stain or dye in the color of your choice for the octopus
- Acorn Brown All-In-One Stain and Finish, or a leather stain or dye in the color of your choice for the soles
- Leather sealer like Pro Gloss Finish
- Strong Leather glue like leather contact cement, tanners bond, or Barge
- Stiff veg tanned leather for the soles - a piece like this Craftsman Oak Double Shoulder somewhere between 7oz and 9oz will work well
- Thinner veg tanned leather for the straps - I used the 4-5oz Oak Leaf Side. You could also use a pre-treated chrome tanned leather, but you won't be able to add the same kind of stamping detail.
- Some kind of foam or rubber if you want to make the soles a little softer - I used some 3/8" craft foam that I happened to have, which seemed to work well
- Two 1/2" silver buckles for the straps
- Paper or oaktag
- Clear ruler and metal ruler
- Swabs or Q-tips
- Disposable paintbrushes for glue
- Pencil - having some pens or pencils in different colors can also be useful when patterning
- A power disc sander or spindle sander, ideally both - sanding by hand will probably work as well, but be much more time consuming, and won't give you as clean an edge. If you don't have access to power sanders, you might also consider using a Dremel or trying your leather skiving tool.
- Optional - an old flip flop that you like the fit of for reference
Step 2: Sandal Anatomy
Before I started making my sandal, I looked through a lot of tutorials and photos online to understand how a shoe like this is constructed. There are a few variations, but the basic structure is always similar.
The upper of the sandal is what you call the straps, or any part of a shoe that goes over the top and sides of your foot.
The sole of the shoe consists of laminated layers that both create volume, keeping your foot away from the ground, and encase the ends of the straps where they are permanently affixed. The number of layers in the sole really depends on how thick you want it to be, but it almost always contains these three basic layers from the top down (my diagram shows a flip flop type sandal for simplicity):
-The insole - this is the very top layer of sole with holes cut in it to hold the straps.
-The midsole - This layer goes right below the insole and has larger areas cut out that accommodate the ends of the straps, keeping them flush against the insole so they don't create an uncomfortable bump under your foot.
-The sole - the very bottom layer which is one solid piece - this can be leather, or some kind of rubber.
I decided to add a low wedge heel to my sandal by stacking layers of leather and sandwiching them between the midsole and the sole in the rear section of my shoe.
Step 3: Designing the Sandal
To design my octopus sandal, I looked at a lot of other sandals for reference, and at a lot of photos of cephalopods. Then I sketched a design that made use of the shape of the octopus, with each tentacle as a functioning strap. I ended up changing my design a little when I began patterning, but the basic idea stayed the same.
Step 4: Designing a Basic Sole Shape
To create the basic shape of your sandal sole, all you really need is your foot and a pencil and paper, but I found that having an old flip flop for size and shape reference was useful.
First I traced the shape of my flip flop onto paper. Then I placed my bare foot inside this outline and traced around it. I traced two lines around my foot: one with my pencil perpendicular to the floor (this gets the basic profile of your foot) and one with with my pencil held at a 45 degree angle (this creates a second line that shows you where your foot is actually making contact with the paper). I also made sure to mark the point between my toes where a flip flop strap would go, and the point behind the ball of my foot on both sides.
Then I looked at all three of these lines and made some aesthetic adjustments of the outer line in colored pencil. I used scissors to cut out my sole shape, and looked at it in relation to my foot again to be sure I liked it.
Step 5: Designing a Stacked Heel
Once I had my basic sole shape, I used it to create a set of patterns for the layers of a stacked heel.
First I traced it off onto a piece of paper, making sure to also copy the two points marking the ball of my foot.
I measured 3/4" in from the edge of the original heel at the back and sides, and drew a new smaller heel that blends into the original toe shape. This is the bottom sole piece.
Then I created a set of 4 heel patterns that blend the largest insole piece into to the smallest sole piece, creating a sort of topographic stacked heel shape.
Once I had my patterns created, I cut them out in cardboard to test how they stacked. After taking a look at them, I decided the heel was too low and that I wanted to add another two leather heel layers. I did this later when I traced the pattern in Adobe Illustrator. Which I will explain in step 8.
Step 6: Designing the Octopus
To create a octopus shape the for the upper of my sandal, I started out by looking at my sketch and drawing an octopus shape on paper that seemed about the right size to go around my foot. I cut out this shape and wrapped it around my foot to check its fit. It took quite a few revisions to get just the right shape, and after several iterations in paper I switched to fabric and eventually scrap leather to get a more accurate fit.
I ended up deciding that it would be best to create the octopus out of two separate layers of leather sewn together. I thought this looked good and helped it fit around the ankle more smoothly.
I also decided to add a strap that went around the back and connected to one of the ankle straps to make the whole sandal extra secure. I designed this strap to look like the end of an octopus tentacle for an extra touch of cephalopod.
Step 7: Fitting the Octopus
When I was satisfied with my design, I marked the location of each 'tentacle' strap on the sole, and then cut out slots in my cardboard pattern to feed the straps through.
I threaded the straps through these slots in the sole, and tightened them to a comfortable place on my foot. then I taped them down to the sole to hold them in place.
I cut two 48" long 1/2" wide strips of paper and taped them to the ends of the leather ankle straps. Then I laced them up my leg to see how long they would need to be. I wanted them to reach up over the top of my calf so they would stay up. I looped them twice around my leg at the top and marked where they met.
Then I used a scratch awl on the straps to mark where each one met the sole. I turned my shoe mock-up over, removed the tape and traced around the ends of each strap. This told me where to pattern the strap cut outs in my midsole.
I scanned the underside of my sole and my octopus upper so I could use them to create Illustrator patterns.
Step 8: Making Pattern Files
I took the scans of the heel and upper of my sandal and imported them into Adobe Illustrator where I traced them with the pen tool.
On the upper I marked the places where each strap should meet the sole with a red guideline. I left one inch of strap beyond these red lines. This is the part of the strap that will be enclosed between the sole and insole. I also marked where I wanted to punch the sewing holes and sucker details on the face of the octopus.
On the sole pattern, I used the lines I had drawn as rough guidelines to create the 6 heel pieces and the sole. I used the offset path tool, and offset each heel section by 1/8" to create the heel layer above it.
On the insole I used my scanned cardboard to mark out the slits where the straps would come through. On the midsole I marked where the strap cut-outs should be, making them 1" long to match the 1" strap overlaps.
I've attached all my pattern files here. I am a US women's size 10, so if your feet are a different size, I would suggest creating your own sole and heel patterns. The upper of the sandal, however, can probably be scaled up or down slightly to fit different feet. Try printing it and cutting it out to see if it needs adjustment to fit your foot.
Step 9: Cutting Out the Sole
Now it was time to start cutting out the leather.
I printed my right and left pattern pieces on a regular printer and then cut each one out with scissors. I lay out my bottom sole piece, 6 leather heel layers and insole from both sides on my thick 8-9oz veg tanned leather and traced them with the sharp tip of my awl. On the insole piece I marked the ends of each strap slot with the awl, and on each heel piece I also traced the guideline that marks where the next heel piece should sit.
Then I used my exacto knife to cut out each piece by hand. This was a long process that required a lot of care. The most important thing I learned was that THERE IS NO SUBSTITUTE FOR A SHARP EXACTO BLADE! Every time I decided to change mine, the difference was amazing. Make sure you have extra blades and change them often. It will make cutting out all these pieces much easier and safer.
Once my pieces were cut out I used hole punches to punch holes at the ends of each strap slit on the insole and then cut out the rest of the slit with the exacto knife.
I traced the midsoles and one layer of the heels onto my craft foam and used my exacto knife to cut them out and remove each strap cut-out. I saved these foam cut-outs to help fill in gaps later.
Step 10: Skiving the Heel
When all my cut heel pieces were stacked together, their inner edges formed a topographic shape like a staircase, which would probably feel weird under your foot, so before I glued the heel pieces together I skived the inner edge of each piece, turning this staircase shape into something more like a slide. Skiving is basically shaving away layers of leather with a tool that looks not unlike a razor.
I used my Skiving tool on the curved inner sides of my leather heel pieces so each one tapered to a thin edge.
The Skiving tool didn't work well on the foam, so I just used my exacto to thin the edge as much as I could.
Step 11: Assembling the Heel
To assemble my heel I laid out my bottom sole and all my heel pieces and then sanded the top grain side of each piece of leather. Working in sections, I spread Eco-Weld contact cement on the top of each piece and the bottom of the next, waited until the glue was tacky and then pressed the pieces together.
I made sure to align each heel section properly with the guideline I had traced on the piece below, and also looked at the underside of the heel each time to check that each piece was sticking out just a little past the one below.
I used a mallet to pound the pieces together for an extra strong hold. When they were all glued together, I used some scraps of wood and thick leather to hold the whole stack together with spring clamps and left them to dry overnight.
Step 12: Cutting Out the Octopus
While the glue on my heel stacks was drying, I cut the main octopus pieces and back tentacles straps out of my 5oz leather with an exacto knife.
I traced them with an awl first and made sure, once again, that my exacto blade was super sharp.
On the upper layer of the octopus, I marked the sewing lines with an awl, and on the lower piece I marked the outline of the octopus eyes.
I cut out the eyes by punching a hole in each corner and then cutting the rest of the eye shape with the exacto.
Step 13: Detailing the Octopus
To add some tentacle details to my octopus, I used two Tandy seeder stamps and my hole punch.
First I laid out my octopus pattern on a poundo board and covered it with saran wrap. I wanted it there for a reference of what the whole octopus looked like with the two pieces together.
Then I used my stitching groover to mark a very light line 1/8" in from the edge of one side of each tentacle as a guideline for where to stamp.
I cased my leather by dampening it with a sponge, then letting it sit for a few minutes.
Then I took my large and small seeder stamps and added sucker details along the edge of the tentacles.
I also punched out the first two or three of these suckers on each tentacle with my hole punch to add more variety.
On the upper layer of the octopus, I used my 1/8" stitching chisel to punch sewing holes along the sewing lines I had marked.
Step 14: Dying the Octopus
Once all 4 of my octopus pieces for each foot were cut and detailed, I dyed them black with Pro Waterstain.
This leather dye works much better than some of the others I've tried and the black easily gives a perfect opaque finish in one or two coats. I used a wool swab to spread my dye over the front, edges and back of each leather octopus piece, and a paintbrush to make sure I was getting dye in all the stamped details and punched holes.
Step 15: Finishing the Octopus
Burnishing the edges of the octopus pieces gave them nice clean finish.
I used a wool dauber to spread Gum Tragacanth on each edge and then rubbed them vigorously with a wooden burnishing tool until they became rounded and slightly shiny.
Finally I treated both sides of each piece with Professional Gloss Finish to seal and protect the leather and dye.
Step 16: Sewing the Octopus
To attach the two layers of the octopus upper, I first glued them together with contact cement, lining them up so the top piece fit correctly over the bottom piece creating the inner outline of the eyes. Then I used a sharp awl and a mallet to punch the sewing holes through the under layer of leather.
To sew the two pieces together I used a leather needle and thick black waxed thread to create a saddle stitch.
There are two ways to do a saddle stitch: the two needles at a time method, or the one needle, two passes method. I've tried both and I prefer the one needle, two passes method. For a great description of how to use two needles see this excellent Instructable by jessyratfink.
To use the one needle, two passes method, I just threaded a single leather needle with a long strand of waxed thread and began sewing at one end of the line of sewing holes. When I got to the end of the sewing holes, I turned around and sewed back the other way, this time filling in the opposite spaces between sewing holes, making the stitches look like one unbroken line similar to a sewing machine stitch. When I got back to the beginning I just back stitched a few stitches to secure the thread before cutting it.
Step 17: Sanding the Heel
By this time the glue on my stacked heels had dried and it was time to sand them.
I used both a power spindle sander and disk sander to smooth and shape my heel. The disk sander was good for the heel and toe area but wouldn't reach into the concave curves of the arch. The spindle sander worked well for those areas. I tried to get the sides of my heel as smooth as I could and made sure the right and left foot were the same.
These power sanders worked well, but the same job could also be done by hand with sandpaper and a bit of patience, or by using a dremmel with a sanding attachment. Another possibility might be to use your leather skiving tool to help even out the edges. In other words, if you don't have access to a power sanders, you can still create a nice looking heel shape.
I hadn't realized before that the section of the leather that I had cut the right foot out of was fuzzier on the bottom than the left foot. I decided I didn't like this so I ended up cutting out a second layer of sole in my thinner leather and gluing it to the bottom of the fuzzy sole. This solved the problem quite well.
Step 18: Punching the Sewing Holes
Before attaching the upper to the sole, I punched sewing holes in the insole. If the midsole was leather, I would have punched holes through both layers after gluing them together, but since my midsole was foam it could be stitched through without punching.
First I used my stitching groover with the 'gouge' head to gouge a groove all the way around each insole about halfway between the strap slits and the edge of the leather. Using the stitching groover is a bit tricky, it's easy to make a mistake and really mess up the look of your insole. Stopping and starting usually causes mistakes, so try to use long, smooth motions, and practice on a scrap piece of leather first.
After making the groove, I cased my leather with water and a sponge and then used my stitching punch to punch holes all the way around the insole along the groove. Changing the heads of the stitch punch to smaller numbers of prongs makes it possible to go around curves.
Step 19: Making Your Mark
Tandy just happens to have an octopus stamp that I couldn't resist using to mark the insole of my shoes. This is certainly not necessary, but it is a fun detail that I really gives the sandals a nice professional look.
I tried to stamp my insoles after I had already cut and punched them. Unfortunately I found that making a clean stamp impression with a stamp this large is quite difficult. As you can see from my last photo, it's easy to get a sort of ghosting if your stamp moves out of place as you are hitting it. I ended up ruining two insoles before I decided I should obviously stamp them before I cut them out so I didn't waste time and effort.
Definitely practice using the stamp, and, if you can, try using a press or clamp to make an impression with this type of stamp instead of a mallet.
Step 20: Finishing the Sole
Once the sole was punched and stamped, I finished the top surface with Eco-Flo All-In-One Stain and Finish in Acorn Brown. I like the rich leathery quality of of this all-in-one stain, but you could use any combination of dye and finish to color and seal your sole leather.
To apply the stain, I used a clean rag and tried to apply an even coat working in small circles. I found that getting a uniform color was a bit tricky, and working fast was very important. When the stain was dry, I buffed it with the rag to give it an extra shine.
Step 21: Attaching the Upper to the Sole
To attach the octopus to the sole correctly, I first used the octopus pattern to mark the place where each tentacle is supposed to enter the slot on the sole. I threaded the tentacles through the slots, and taped them down to the bottom side of the sole. Then I tried on the sandal to make sure the fit was right and adjusted the straps accordingly.
To attach the insole and midsole, I first removed the tape and glued the undersides of the straps to the bottom of the insole with contact cement. Then I glued the foam midsole onto the bottom of the insole, making sure to line it up correctly so the ends of the straps fit into the cut-outs. I cut the little foam cut out pieces from the midsole in half so they were thinner, and used them to fill in the gaps above the straps.
I used a hammer on the soles to made sure the two pieces had a solid connection, and even put the shoe on and put all my weight on it to press it together really firmly.
Finally I used scrap wood, leather and spring clamps to hold the soles together so they could dry overnight.
Step 22: Sewing the Sole to the Midsole
Once the midsole and insole were glued, I sewed them together using a saddle stitch. This gives them an extra strong connection and also looks nice.
Once again I used the one needle, two passes method, I threaded a single leather needle with a long strand of waxed thread. I pulled the thread through one of the holes on the shoe until there was about the same amount of thread sticking out on both sides. Then I sewed around the shoe with the needle end of the thread.
When I got back to where I started, I switched the needle to the other end of the thread and started sewing back around in the opposite direction.
If I ran out of thread at any point, I just back stitched a few stitches, cut off my thread and started a new thread. Since the bottom side of the stitch line is going to be coated with glue anyway, it's unlikely the stitches will come out.
Step 23: Attaching the Heel
To attach the stacked heel to the upper sole layers of the sandal, I used the same gluing method I used for the other heel layers. I made sure to line the pieces up precisely and press them together very firmly. I clamped the layers together in as many places as I could and used scraps of thick leather to protect the top of the insole. I left the whole thing overnight to dry thoroughly.
Step 24: Creating the Straps
While my glue was drying I created the extended straps that will go up the leg. I used Tandy's strap cutter to get 4 straps that were an even 1/2" wide and 45" long, but you could also do this with an exacto knife, or you could order pre-cut 1/2" straps.
Once I had cut the straps, I lay them out on a piece of saran wrap, dyed both sides of them with black Waterstain and finished them with Pro Gloss Finish.
Step 25: Sanding the Finished Sole
With the layers of the heel all finally glued together, it was time to sand them to make them look even and finished.
I did this using the same of combination of a power disc sander and spindle sander. You could potentially sand this by hand, but it would be more time consuming, so I definitely suggest using power sanders, or perhaps trying a leather skiving tool, or a dremmel with the right attachment.
Before using the sanders, I made sure to tape all my loose strap ends inside the sandal so they wouldn't get caught in the sander. I used masking tape which didn't leave marks or damage the finish of the straps.
Then I used the disc sander to get all the areas of the heel edge that had convex curves, like the toe of the sandal and some of the heel. I switched to the spindle sander to sand the arches. Tilting the bed of the spindle sander enabled me to sand the angled back and sides of the heel.
I tried to sand both heels as evenly as possible. It was a bit of a tricky process, and it definitely required some concentration.
Step 26: Adding the Straps
The next step was adding the long straps and buckles.
To do this I connected one end of each long strap to the short straps on the ankle of the octopus upper using two small black rivets.
Then I wrapped the long straps up my calf and marked where they met right below my knee on the outside of my leg. I attached a buckle to one of the strap ends, and punched a series of holes 1/2" apart in the other strap end.
Step 27: Finishing Details
Finally, to give the sole a really nice, finished look I used my edge beveler to soften the top and bottom corners of the sole.
Then I treated the stacked sides of the heel and sole with Pro Gloss finish to seal it and give it shine.
Step 28: Long Walks on the Beach
Now that my sandals were done, I took them to their natural environment and let them stretch their tentacles.
I think the long straps look and feel good either laced up the leg, or wrapped around the ankle. The low heel is a nice height that gives the shoe an interesting profile, but it still easy to walk in, and I like the fact that the octopus design is subtle enough that you don't necessarily notice it at first glance. I have definitely never seen a pair of sandals quite like this, and the fact that I actually made them myself makes them all the more fun to wear.
My first foray into making footwear was an interesting adventure. There is something very satisfying about understanding a bit about how shoes are made, and it definitely opens up a whole new world of design possibilities.