All images from Yale's recently opened Art Image library that can be found here.
From top to bottom:
1. Joseph Albers, Homage to the Square, color screenprint, 1962
2. Jean (Hans) Arp, Composition, color lithograph, 1955
3. Max Ernst, Oiseau, color etching, 1957
4. Maurice Esteve, Rue Monsieur le Prince, color etching, n.d.
5. Takesada Matsutani, Fly-A
6. Joyce Wieland, O Canada