Convex and Concave is one of Escher’s best-known works, a narrative print brimming with elements that can be interpreted in two ways. Nigh on two years later, in February 1957, he created a lithograph on the same subject, albeit with an image that is a lot more concise.
Cube with Ribbons combines a cube that allows for just one interpretation and some objects that can be convex or concave and can be positioned in front or behind. Two ellipses intersecting at right angles have been widened into ribbons. Each of these four halved ellipses can be rotated towards or away from the viewer and each intersection allows for multiple interpretations. The decorations on the ribbons can be seen either as protruding hemispheres with a central dimple or as a dimple with a central hemisphere.
Compared to Convex and Concave this seems like a simple print but appearances can be deceptive, as Escher shows so consistently in his work. By encouraging the viewer to make these double interpretations with simple shapes, the viewer is kept looking for the logic behind these Möbius strips filled with craters and/or Toffifee candies.