These Op-Art-style socks feature interlocking squares and triangles in a tiling pattern. This design is a type of tessellation, a pattern of shapes that fit together with no overlapping or gaps. The sole is worked in the houndstooth pattern, a famous example of optical illusion—as you view it, everything appears to rotate clockwise.

FINISHED SIZE About 7¼“ (18.5 cm) foot circumference, unstretched, and 9 (9¾)” (23 25 cm) foot length from back of heel to tip of toe (length is adjustable). To fit U.S. women’s shoe sizes 6–7 (8–9); European sizes 36–38 (39–41). Socks shown measure 9¾“ (25 cm) in foot length.

YARN Austermann Step Classic (75% superwash wool, 25% nylon; 459 yd 420 m/100 g): #1019 green (MC) and #1023 teal blue (CC), 1 ball each for both sizes.

NEEDLES U.S. size 1 (2.25 mm): set of 4 (or 5) double-pointed (dpn) and two 24” (60 cm) circular (cir). Adjust needle size if necessary to obtain the correct gauge.

NOTIONS Tapestry needle.

GAUGE 36 sts and 48 rnds = 4” (10 cm) in solid-color St st, worked in rnds. 37 sts and 40 rnds = 4” (10 cm) in charted patts, worked in rnds.