The optical illusion is created by an unstable visual perception that leads the beholder to vaccilate between two or more interpretations. The reversible cube in this design consists of two squares that represent the front and back side of the cube. The tiling arrangement lets the cubes be viewed from above or below. Because both interpretations are valid, the viewer’s eye often causes the image to flip back and forth between the two possibilities. Josef Albers (1888–1976) used this effect for his 1942 work Prefation.

For these socks, named after Josef Albers, I worked the leg and instep in two-color shadow knitting following a modular technique in which sections are built one upon the other. The heel, sole, and toe are worked in a solid color.

Sizes: About 7¼ (7½)“ (18.5 [19] cm) foot circumference, unstretched, and 9¼ (10¾)” (23.5 [27.5] cm) foot length from back of heel to tip of toe (minor length adjustments possible). To fit U.S. women’s shoe sizes 7–8 (men’s 10½–11½); European shoe sizes 38–40 (42-44)