Sun and Moon

Woodcut in blue, red, yellow and black, printed from four blocks.
 
This woodcut is Escher’s first example of a non-periodic tessellation. Take a close look: there is no symmetry within the image. The watercolor of this symmetry reveals that with slight alteration of the borders the whole group of birds can be repeated, making it a periodic tessellation! Escher used a mirror image of the same birds in his lithograph Liberation. (Bool 400) Here the overlapping night sky and morning sun create an unforgettable background and his most colorful print to date.