For students of the denim game, it’s all about authenticity. Every detail got to be just right, and even the machinery used to perform certain details got to be right. Let’s talk a bit about the stitching at the bottom hem and the coveted Union Special 43200G. For advocates of all things pure and authentic, the hem at the leg opening should be a chain stitch. With a chain stitch you get nice break in possibilities because of the opposite pull of the denim, which creates a roping effect when you wash your jeans and the fabrics is exposed to some shrinkage.
In the 60′s Japanese denim manufacturers started buying every Union Special 43200G on the North American market. So, when Union Special stopped making the machine in 1989, the market was pretty much out of the old school machinery that would create that old look. Denim enthusiasts all across the US started looking to for a 43200G to get their hands on, but the Japanese had done a brilliant job buying almost every machine left.
But, no matter how true or authentic the chain stitch might be, it does have some cons. It’s constructed in a way that the sewing machine loops a single length of thread back on itself. If a thread comes loose however, the whole chain could unravel. Most jeans sold today don’t have chain-stitched hems, but of course our jeans all have chain stitches. In the 80’s, the denim industry started using lock stitching instead of chain stitching. Chain Stitching was faster to produce, but the lock, or single stitch is both sturdier and cheaper to produce.