I guess maybe I’m just a super nerd about garment construction, but I think that it’s important to understand old-world techniques, and why those techniques are still sought after today. The little details that made a pair of jeans last 3 years instead of 3 months, or kept a work shirt together wash after wash. This is all about the way things used to be.
The original standard for hemming a pair of denim was the chainstitch, which is a looped stitch resembling the links of a chain. The forms a very sturdy and heavyweight stitch that not only allows for a more sturdy cuff on your denim, but it’s also visually appealing and noticeable if you’re wearing a single-cuff. The Union Special 43200G was the first machine that was able to do this type of stitching, and the majority of your denim shops (Self Edge, Super Denim, Rogue Territory) still use this exact machine to hem denim. A chainstitched hem will also cause a “roping” effect on the jeans, causing the denim to warp around the hem due to the stitch; this really becomes visible after a few washes and some heavy wear.