Modified grids, chessboards, or figures filled with alternating black and white lines are often used for spatial sensation in op art. Tilted lines and grids are as effective as rectangular ones. Günter Fruhtrunk (1923–1982) used this effect for some of his works in the 1960s.

For this sock pattern, named after Günter Fruhtrunk, I worked a striped yarn in a simple k3, p1 rib pattern that’s truncated with decreases and increases to form a strong diagonal pattern. The direction is reversed on the right and left socks.

Sizes: About 7 (7½)“ (18 19 cm) foot circumference, unstretched, and 10 (11)” (25.5 28 cm) foot length from back of heel to tip of toe (length is adjustable). To fit U.S. women’s shoe sizes 8½–9½ (men’s 10½–11½); European shoe sizes 40–41 (45–46).