Fingering weight slubby yarn with a slight sheen. Great for just about anything that utilizes simple stitches. The yarn slubs are the superstar and complex stitches could get lost in the texture of the yarn.
90% Superwash Merino 10% Nylon - 438 yds/100g skein
Check out this great pattern on Ravelry for a great basic top down sweater using Bumpy:
https://www.ravelry.com/patterns/library/go-to-sweater