Since we make our signal flags we tend to go through a lot of thread. We use a semi-industrial sewing machine, Grand Quilter by Pfaff. After doing a lot of research and finding this article “Is There A Difference In Sewing Thread Brands? You Be The Judge!” which has a great article and pictures of what some of the different thread and how they look through magnification. We use Mettler Thread which produces great results. The picture below shows just a couple close up.
Choosing the right thread is important because it ultimately can extend the life of the machine that you are using. It also affects tension and can make the difference between a professional looking end product or cheap looking product.
Mettler has worked great for us but is getting harder to find as far as the bigger spools. Quite a few places online carry the little size which is about 164 yards. Since we do a lot of sewing we normally look for the larger spools like the 574 yds or the 1024 which is difficult to find in Navy and Red. It seems that you find a great product and learn to depend on it and it vanishes never to be seen again.
We just bought quite a bit but hope they continue to have it. If you can find it I would recommend this thread as it really does a great job.