You can see the yarn trimmings if you turn the Paper Fiber Socks inside out. Is there a reason for this?
To produce a taping effect, these socks employ not only a different type of knitting but also a different type of yarn in the taping section. Sock knitting machines, by their nature, are not cut-and-sew machines, and therefore, cannot sew, adhere, or do other finishing work with the ends of the inserted paper-yarn. For this reason, the ends of the inserted yarn remain slightly in excess to prevent it from casting off.
If there are less yarn ends remaining, the section with the different yarn type will become loose and start to detach.
Especially in the longitudinal arch support section, there are parts where the stiches are not in parallel and switches to vertical or angled, resulting in the yarn ends remaining in these parts. On top of this, some extra yarn must be left over, and accordingly, yarn ends remain.