In my latest adventures with leather, I have been researching and experimenting with different threads, needles and trying to achieve the perfect stitch. While asking my good friend Google questions, I came across a forum post by a factory worker who sews leather items and he mentioned not to waste money on thicker thread and just use a regular, good quality thread. It really won't make a difference. This is good to know BUT I really, really love the look of those thicker threads on leather. It adds to the personality of the bag - especially when the stitch is nice and done in a contrasting colour.
So far I have tried: Gutermann polyester thread, Gutermann extra strong thread, Coats and Clarke all purpose thread and lastly, Gutermann upholstery thread.
The all purpose threads - they work. They work really great actually. They are quite tough and the seams seem to be fairly sturdy. They just don't show up very well and that's not the look I am going for!
The extra strong thread works but I found I needed to use a bigger leather needle (100/16 at least) so the thicker thread would go through the needle without fraying. This is a problem however because I've found that the smaller leather needles go through multiple layers of leather a lot easier (go figure!) My bobbin casing DEFINITELY does not like this thread and it would fray immediately. This one is out!
Gutermann upholstery thread - after hours and hours of research and a lot of trial and error I think I've finally figured it out. This is a very thick thread and looks really great. Pros - can be threaded into a variety of needles sizes and works perfectly fine in my bobbin case. Cons - not many colour choices at my local store and I find the end does fray and unravel quite easily. HOWEVER, here is what I had to do so my stitches came out perfectly top and bottom:
1. lower bobbin tension almost to the lowest tension
2. use my maximum top thread tension setting (mine is 9)
3. go with a bigger needle size than my usual 80/12 leather needle. I can manage with a 90/14 but found it better with a 100/16.
Here is the end result:
I'm a pretty happy girl. I'll have to give it a try with my next bag!