Sewing Leather: a few notes

A friend recently asked me about sewing leather. Since I had recently sewn a leather jacket for an acquaintance’s client, I said I would jot down some notes.

For the most part, sewing garment leather is similar to sewing a heavyweight denim, which is about 14 ozs or heavier. (Joann Fabrics’ denims are mostly 12 ozs.) If you can sew denim, you can sew garment-weight leather. You will encounter some of the same challenges but there are also things that make sewing garment leather more enjoyable than sewing denim. For instance, leather doesn’t ravel, so you don’t have to finish the edges!

Leather

Leather thickness is indicated by its weight in ounces. Each ounce of weight equals approximately 1/64″ of thickness. So a 4-ozs leather would be about 1/16″ thick. Garment leather weights range from 1 ozs to about 2.5-3 ozs. I find 1-1.5 ozs leather is approximately equal to heavy denim. A couple of sources for leather are Tandy Leather and Fashion Leather International.

Equipment & Materials

One needs a couple of specialized things for sewing leather. Of these, I’d say a Teflon foot and leather needles are the only absolute must-haves.

Teflon foot
An absolute must-have! A regular metal presser foot will drag on leather’s smooth finish, as counter-intuitive as it sounds. There is less drag when sewing with the leather’s sueded side up, and most seams are right side (smooth side) together and sueded side up, but topstitching will be on the smooth side. A Teflon foot allows leather to glide under the pressure foot without dragging.
Leather needle
Regular needles’ round shank makes a series of holes which turn the stitching line into a perforation. The perforation will make the leather tear more easily. A leather needle‘s tip is blade-like and is positioned at an angle to the stitching line.
It makes angled slashes rather than holes, which helps resist tearing.
Seam roller
To flatten the seam allowances in leather, since you can’t press or use steam, you use a seam roller. A seam roller resembles a paint roller except with a narrow, hard, roller. I would guess that you use it by position the seam allowance over a sleeve roll, or maybe a length of 1″ wooden dowel, and firmly roll the roller over the seam allowances, flattening it.

seam roller, with rounded edges

Seam roller, with square edges



I don’t have a seam roller, so I burnish the seam with the rounded bottom edge of a small empty mayonnaise jar. The jar’s rounded bottom edge reduces the chance of marking the leather.

You can optionally glue the seam allowances down with rubber cement.

Rubber cement
I use a rubber cement by Tandy, called “Tanners Bond”. Its main properties are adding little bulk and remaining flexible over time.

Tandy “Tanners Bond” rubber cement

Thread
I use normal all-purpose polyester-wrapped cotton thread. For top stitching, I use top-stitching thread for the upper thread and all-purpose polyester-wrapped cotton thread in the bobbin.

Techniques

Cutting
I cut leather the same way I cut fabric: with a rotary cutter, on a cutting mat.
No pins! No glue!
You can’t use pins in leather because they will leave permanent holes! One possibility is to use basting glue, but I have not tried that. I have heard of using small bulldog clips for “pinning”, but I have found that they don’t work well enough to be worth the bother.

bulldog clips

Stitching seams
I recommend a technique called “stretch sewing”. David Page Coffin explains this in his excellent book, “Shirtmaking: Developing Skills For Fine Sewing“. The technique is similar to sewing stretchy materials such as knits or swimsuit material. Grab hold of the material in front and behind of the needle, with your hands about 8-12 inches apart, stretch the material and keep it taut as you firmly guide it under the needle as you stitch the seam, neither pulling nor pushing against the sewing machine’s feed dogs. By keeping the material taut, you give it some tension and structure, which helps resist puckering or wandering. This is a similar concept to “hooping” fabric for embroidery, where the fabric to be embroidered is held stretched taut in a hoop. The taut fabric resists deformation.

A side benefit of stretch sewing is that holding on tightly to the material reduces the need to pin.

Gluing seam allowances

Glue seam allowances down with rubber cement.
Application is different than with normal rubber cement. Apply to both surfaces and wait until it dries, changing from milky to clear, then lightly press the surfaces together. Light pressure allows re-positioning of the pieces as necessary. When satisfied with the placement, press firmly to seat the bond.

You can also hem garments this way: fold the hem allowance up and glue.

Stitching multiple layers
Sewing garment leather is very similar to sewing heavy denim. Stitching across multiple layers of leather requires the same technique: guide the garment forward under the needle if the feed dogs fail to move it forward. Manually turn the wheel to help push the needle push through bulky areas.
Flattening seams
You cannot press or steam leather, so you’d use pressure to “press” leather. I used the aforementioned mayo jar as my seam roller/presser. Just bear down on the seam on a hard surface. A few dab of rubber cement helps keep seam allowances where they should be.

Issues/Problems

I had one issue which may be specific to my machine/thread combination: many skipped stitches and frequent breakage of the upper thread. I eventually stumbled on a fix: a drop of oil on the bobbin carrier’s thread groove. This fixed the problem, but I have no idea why! (In fact, I later found out that the machine’s manual does call for a drop of oil at that location!)

1 Comment on “Sewing Leather: a few notes”

  1. #1 Susan Menta
    on Nov 9th, 2012 at 15:23

    Thanks for the roundup of info Andy. Love the mayo jar idea for rolling the seams. I think we’ll definitely be looking forward to playiing around with some scraps under your guidance at the meetup soon.