SLF is a little bit curled fiber but really little bit and it is flat . It is very similar like polar fiber .But in our opinion, polar fiber is a little bit thicker and stiffer. SFL is thinner and softer than polar fiber.
This material has already become a classic in tying, mainly for Caddis/Sedge larvae and shrimps . It is a water stable and very easy to work with. The fluorescent colours are ideal for shellbacks for shrimps.