Linen yarn provides nice drape for a summer vest with the outline of Strawberry Mountain in Grant County, Oregon outlined in lace and double moss stitch around the bottom.
Pattern calls for:
800(900,1000,1100,1200,1350,1500)yds Classic Elite Yarns Firefly(75%viscose/25%linen 155yds/50g) Color # 7755
Also shown in Elann Canapone hemp yarn (beige) which was (it is discontinued) listed as DK, but knits like fingering/sock weight.

Currently available only in the ebook