Leather is durable and beautiful. It's appearance is individual and unique. There is no grain that needs to be followed, thus bag pieces can be moved around to fit without worrying too much about which way is up. Some disadvantages are that it can be a bit bulky to sew, and care needs to be taken when cutting out, to avoid marks and holes. Care also needs to be taken to avoid creating new marks or holes when sewing it together.
I am working on my strap for my red leather City bag. I had cut a piece of leather for the bag, and discovered it had some flaws, so have used it to make a test strap. Whilst the photo above looks great from the right side, you can see from the photo below, that it would not be strong and durable enough to be carrying around a largish handbag on a daily basis.
The join would gape and wear and catch on things....
So I will go with an overlap underneath the stitching. Kind of like the image below. Only I will be more careful and neat and hopefully my thread will not break whilst trying to do it on the real thing...
A few things that I have learned whilst sewing leather...
1. Use heavier thread - I'm using Gutermann upholstery thread. It is heavier than regular Gutermann thread. A 100m spool of upholstery thread is about the same size as a 250m reel of regular sew-all thread.
2. Use a longer stitch length than usual. I usually use 3, for leather I use 4 (For stuffed toys I use 2.2, which is the default for my domestic machine)
3. I use my industrial machine for leather, with a teflon foot, some people use a domestic machine and a walking foot. I have heard that the best is an industrial machine with a roller foot. Industrial machines are generally designed to one job well. I don't have the space (or money) for enough industrial machines to suit all my whims and fancies, so what I have will need to do!
4. With leather you need to sew it right the first time. If you make a mistake, and unpick it, you will be left with unsightly holes.
5. You cannot pin leather for the same reason. I would like to thank Amy Karol of "Angry Chicken" for this video "I don't pin, 'cause I don't want to" that encouraged my disdain for pinning as it is really helping me out now. I do use the odd bobby pin for bits where I am less than confident. Other people have suggested hair clips and bull-dog clips, but my bull dog clips have gone walk-about?
6. I discovered that the feed-dogs on my machine chew the leather a bit. It's not pretty. Reducing the foot pressure helps a little. Placing something between the leather and those nasty teeth also helps. I have been using the odd bit of tear-away. If anyone has any better ideas I would love to hear them. Most of the time, except for straps, the feed-dogs don't need to go near the top side of the leather anyway.