Fair Isle Jumpers, Tanks & Cardigans Barbour Case Fair Isle Jumper In Navy Marl Fair Isle Jumpers, Tanks & Cardigans The Best Fair Isle Jumpers, Including The John Lewis 49 Favourite Fair Isle Crew Neck Jumper Barbour Case Fair Isle Jumper Cooast. This crew neck sweater is knitted with a colourful Fair Isle pattern framed by contrast ribbing at the collar, hem and cuffs. Crafted in super soft lambswool, this distinctive piece is finished with a signature flag label at the side seam.