Leather Soles for Felted Slippers

I like to use leather soles on felted slippers.  Soles extend the life of the slippers and give feet added protection.  They also give a little extra grip - though from personal experience I can tell you they still slide pretty good on wet wood laminate flooring!

I'm going to talk a little bit first about materials etc. and finish up with MY technique for sewing soles on by hand.

I choose to keep my slippers `all natural` by using leather - this is important to me.  If you are not worried about sticking to natural materials you can paint a latex coating onto the slipper bottoms to give grip.  Several coats are needed and it must be done in a well ventilated place.  I have not tried this for several reasons, the main reasons being:
  • I don't like the idea of painting a substance onto my felt - as soon as you start it is irreversible; you are stuck with it if you don't like it or make a mistake.  At least with sewn-on soles you can undo the stitches and begin again.
  • I have heard that painted on latex reduces the thermal benefits of felt (you feel the cold floor through it) which for me is a BIG no-no.
 If you don't want to use leather for your sewn-on soles you can always experiment with other materials..  how about recycling an old wet-suit?  Or some other rubbery material?  Otherwise a piece of thick felt made from a hard wearing wool (i.e. Norwegian, Gotland, Icelandic) felted really good and hard, as much as it will possibly go - you can cut & sew these on the same as leather.  I have made thick felt soles, stitched them on then coated the sole bottoms with latex.. this way the latex doesn't effect the thermal quality of the felt slipper.

Glue vs Stitch
I am told that it is possible to glue leather soles on to felt slippers.  Fred Aldous recommend a latex glue for this.  Personally I have not tried this... I have all the same concerns that I have about applying latex soles.  In my humble opinion stitching is best.  It will no doubt take longer - but lets be honest here felt slippers aren't exactly a quick job anyway, after going to all that effort why opt for the quick fix to finish them?  I would rather 'do it right' or not do it at-all.

+ Stitching is reversible, you can change your mind & start again.
++ Natural Materials!

-Takes a long time
- Can be hard on your fingers

What sort of leather?
There are lots of different sorts of leather available. If you ask leatherworkers / leather sales-people which are the most suitable for felted slipper soles they ALL have a different opinion - so far none of their suggestions have worked for me. 

My favorite is a soft, flexible leather, 1.2mm to 1.4mm thick - top grain, not a split.  My leather supplier Leather Hides UK sell it as 'craft leather' in many lovely colours.

Slipper soles made from craft leather are soft, lightweight, unobtrusive - they feel like a second skin.  Because the leather is soft it is a LOT easier to work with and your stitches should bed-in slightly being as the leather has 'give'.. it seems to be much more forgiving on the stitching.

It is worth remembering that if you walk on the stitching it will wear out sooner or later. Your choice of leather and thread will make a big difference here. Always choose the strongest thread available to you and double up, plus I always anchor the stitching a regular intervals in the hope that when the stitches wear out, only the small section between anchor points need be replaced.

Slipper soles made from craft leather are soft, lightweight and unobtrusive – they feel like a second skin. Because the leather is soft it is a LOT easier to work with. AND your stitches should bed in slightly, the leather has `give` and seems to be more forgiving on the stitching. I find my hand sewn soles with exposed stitching last much better with soft leather.

As well as craft leather you will find very suitable leather available in the form of old leather coats / clothing, sofa coverings etc. that you can recycle. You can use suede leather too.

I mentioned leather splits earlier, these are basically thick/heavy suede and they are stiffer than top grain leather of the same thickness. The main problems I have encountered with this are:

1. The stitches wear out fast
2. Soles go slimy if you walk on a slightly damp floor
3. Very hard on the fingers to sew (even after soaking to soften)

With any thick, hard leather soles you will wear the hand stitching out quite quickly. Unless you choose a sole-leather thick enough to carve a groove through which you run your stitches; personally I think these would be cumbersome on slippers... for outdoor shoes it may be worth giving it a go.

I also know of people sewing on a first leather sole then gluing a second leather sole over the top, so there are no stitches on the walking surface.

Ready made Soles
You can buy ready made soles and stitch them on.  soles with the holes punched in for you.  These are a couple of suppliers I know of but have never used:
JoesToes in the UK sell slipper soles in all adult shoes sizes in a wide range of materials and colours.. inc. latex covered felt, leather and vibram rubber, with the holes punched in.  
Simpleshoemaking  sells an outdoor (rubber) sole with a suede edge

Let me know how you get on with them if you buy any :)

This is how I do leather soles

Put your feet or suitably sized lasts into the slippers and draw around them onto paper, keep the pencil straight so you stay close to the foot. If you angle the pencil inwards your soles may be too small, angle it outward and it will be too big.

For boots I add a `bumper` to the back of the heels, with normal slippers I add a lip which just comes up the back of the heel a little bit. The heel takes a lot of wear and tear, both when walking and sitting – this moves your stitching to an area where it won’t be constantly abused.

Cut out the paper templates, check they are pretty much the same (doesn’t matter if they are not exactly identical). Draw around them onto the back of the leather, making sure that you have a left and a right sole.

Cut out the leather soles.

Pre-punching the stitching holes will speed up the sewing and reduce wear and tear on your fingers.

You will need:
Either a tool for punching holes in leather OR:
• Piece of wood to place beneath the soles as you punch holes. It will get lots of holes in it so don’t use your nice chopping block!
• Hammer
• Awl. I have a customised (filed down) screwdriver. You want the holes to be between 1mm & 2mm – no more or less.

Place a leather sole right side up on the wooden block. Imagine a line going all around the sole 5mm in from the edge – this is where you will make all the holes (see diagram). Position the awl on the imaginary line and give it a couple of taps with the hammer. Your awl is now most likely stuck a little way into the wood, pull it out and move on to the next hole. Each hole should be 5mm from its neighbours – go all the way around. If you awl has a straight or diamond shaped end, line the long edge up with the edge of the sole for every hole (if you don’t the stitches may a. Look uneven & b. Rip through when pulled tight).

Position the sole onto the correct slipper, and using straight pins pin it into place. You will need to be careful not to stab yourself on these pins as you work (I’ve done it many times). You can do this on or off the last whichever you find easier.

• Work in good light
• Plaster fingers if they get sore
• Use hemostats (artery clamps) to help pull the needle if needed. A thimble may help too.

I use a normal needle (not a special leather needle) that is big enough to handle with comfort and not bend too easily. Thread up with strong thread, cut to twice the length you want and doubled up (I use approx 2m thread giving 1m to work with). Secure thread beneath the edge of the sole part way along the inside, take a stitch to bring you back out at the edge.

As you sew remember:
• Stay close to the edge of the sole with your entry points or you may cause the felt bottom to pucker.
• Take care to go INTO the felt enough to secure each stitch... if you don’t it will pull through.

Diagram showing anchor points I use.  Note the shape: this is a boot sole with a heel bumper

Scoop the needle diagonally through the felt, going well in but not ALL the way through to the inside, coming up through a hole in the leather sole. Take a straight stitch back to the outside edge, put the needle back into the felt and again scoop diagonally to the next hole in the sole. Pull each stitch through firmly, and make sure the stitches don’t slacken as you move on. Every couple of inches create an anchor point; stitch through one hole several times, cast off, and carry on stitching – don’t cut the thread. I use more anchor points at the toe and heel as this is where the stitches are most likely to wear (see diagram). When you reach the starting point stitch past it for a few stitches. Cast off well.

One down - one more to go!

There is no way around it – sewing leather soles on by hand is hard work and time consuming. I have learned what works best for ME through trial and error (in no short measure). I am hoping that my experiments with different leathers and techniques might be of help to you as you discover what works best for YOU.

I found it pretty much impossible to find information or advice regarding hand stitching leather soles to felted slippers. I am hoping that this post will be helpful to other seekers

Please feel free to contact me (through comments, or flickr / etsy / folksy mail) if you have some tips or advice to add to this.