In this post, I want to address some of the pros and cons between machine stitching and hand stitching leather products. It’s a personal preference that I hand stitch my leather pieces. Not being able to afford a good sewing machine might be another reason... In no way do I think one process is better than the other.
Pros Of Machine Stitching
Reduces Stitching Time Dramatically
It’s no question that sewing machines are waaaay faster than what anyone single person can hand stitch. This increases efficiency when demand is high and also keeps costs down. You’re able to produce more pieces with less time as well as quickly go through the mistakes should they occur. You can prototype certain ideas without fear of having committed too much time already.
Machines now a days have a laser sight just above the bobbin that allows the user to stitch in a perfectly straight line. Also, the stitches tend to be a lot more uniform in look since the machine can consistently produce the same results over and over again.
Dozens Of Decorative Stitching
Modern sewing machines have the ability to switch how the bobbin punctures the leather which then creates a unique pattern throughout the stitches. A single machine can have as many as 24 stitch patterns. Kind of crazy to think that there are so many ways a single bobbin can go through leather. The image below illustrates a large amount of stitching patterns available to some sewing machine brands (I think these patterns came from Singer).
Cons Of Machine Stitching
Sewing machines have a single needle that pass through the leather. So when stitching, the cross of thread in between the top and bottom of the piece is what is holding the leather together. This causes a lot of rubbing along the threads which wears the thread down over time with normal use. An example of a type of stitch a machine uses is called the “locking stitch.” It requires 2 spools of thread that when stitched, create a dependency on each other. They are stitched in such a way that when 1 thread is severed, it compromises both top and bottom stitches and unravels up to 4 stitches.
The machine employs an under-deck mechanism -- either a "looper" or a "shuttle hook wheel" -- which traps the thread from the needle above, forms a loop or "chain" and binds the two layers of fabric, leather, etc. together. If you look at the machine-stitch or "lockstitch," you can see that the top thread (the "show thread" you see when you look at the top of your strap) is trapped by the "bobbin thread" in the middle of the strap's layers or leather. These two separate threads "saw" at each other in the center of the assembly. Synthetic thread stretches and flexes (unlike linen thread!) so, over a period of months and years, the threads wear at each other, and typically the thinner "bobbin thread" will cut through the heavier "show thread" causing a stitching failure.
Learning Curve Varies
Each sewing machine brand has their own intricacies that can be difficult to understand sometimes. Most machines aren’t manufactured in the states so their translations are sometimes inadequate.
There are some sewing machines that cost $100-$200 dollars that can get a really simple job done but the strength and complexity needed to do larger pieces will drive the price of a decent machine to $600+.
Restrictive Thread Sizes
Most sewing machines accept a thinner thread when stitching; typically around 0.4mm thick. This range in size allows the leather crafter to dictate the visual aesthetics based on the type of piece he/she is making. This also allows the freedom to control linen strength of any leather piece. Saddle leather for equestrians should be made a lot stronger than say a minimal card wallet.
Pros Of Hand Stitching
Hand stitching uses two separate needles, instead of one, and each needle passes through each hole from the opposite sides of the piece, forming a matrix that doesn't bind the threads to each other, but binds the leather instead.
Saddle stitches are much stronger, much more durable, and much less likely to fail. The two threads bypass each other, instead of trapping each other in the stitch-hole: This means no friction and far less likelihood of breakage. If a saddle stitch fails, the thread will not unravel.
Any Thread Size Desired
When hand stitching, you’re allowed to use whatever size thread your needles can fit; from 0.2mm all the way up to 1.2mm. This will have a large hand in the overall aesthetics of the leather piece.
Cons Of Hand Stitching
Longer Stitching Time / More Effort
It takes a leather craftsman with lots of experience in hand stitching to consistently sew with high quality and with any speed, however, it is much much slower of course than when a machine is used. Thus, there is a huge cost differential between hand sewn leather goods and machine sewn leather goods. Hand sewn leather products usually cost multiples of the price of those sewn with a machine.
Higher Chances Of Inconsistent Stitches
Each tug on of a stitch has to be consistent throughout the stitching process, otherwise you can have a stitch that dropped or isn’t as slanted as the other stitches.
How To Identify A Machine Stitched Piece vs A Hand Stitched Piece
1. Check if the threads are different colors on the inside and outside. On some multi-color products the manufacturer uses threads that match the color of the leather they are sewing through. If the threads are different colors inside and outside the product, then the product is most likely machine sewn as it is not possible to have two thread colors if the product is hand sewn using the saddle stitch method.
2. Check if the threads are different sizes on the inside and outside of your product? If they are not the same size then there is a good possibility that the item is machine sewn. This is due to the lower bobbin size restrictions in a typical leather sewing machine many times requiring the use of a smaller thread than the top outside stitch.
3. Look on the inside or back side of your leather product. Can you see small bumps in the leather where the threads come through? This is caused by needle pressure against the leather just prior to piercing the leather and is a telltale sign of machine stitching.
4. Look along the stitch row on the outside of your leather item. Can you see repetitive impressions in the leather along the stitch row? These marks are usually made by a sewing machine as it passes over the leather. This is especially visible in articles sewn with vegetable tanned leathers.
All in all, it’s a matter of the crafters preference for what he/she is trying to accomplish with any leather piece. I think the main driving factor for why crafters still hand stitch their pieces is because they are unwilling to compromise on quality. They are willing to forego the economics of machine stitching their pieces because they appreciate the nostalgic significance.