- Men's chalk white shirt - Mao collar, long buttoned sleeves - EASY-REGULAR shape, 100% linen - Button closure, IKKS button left cuff - IKKS #actforbetter: material containing 100% linen certified Masters of Linen® and European Flax® Are you a fan of white shirts for all occasions? Don't miss the midsummer version, in 100% linen, certified Masters of Linen® and European Flax®.