I noticed a small detail on the hems of a 505 LVC I was hemming for a client.
The end of the stitching on the hems had a smaller stitch length compared to that used on the entire hem. Sewing the hem like this with a chain-stitch caused the looping thread to bunch at closer intervals which effectively prevents the chain-stitch from unraveling through daily friction without the need to be tied down.
It is an interesting sewing method that looks a little ‘coarse’ but is yet a good reflection of the Levis company and their earlier developments and pursuit to manufacture a jean with the greatest amount of efficiency.
Although this could just be the handy work of an individual in a factory who decided this is the way they choose to sew hems. It is by no means an indication of whether this is or has ever been the preferred method by Levis.
Go to your wardrobes and check yours!!