Nineteen Greys (Schubert 8)

Bridget Riley (b. 1931) Nineteen Greys (Schubert 8) the complete set of four screenprints in colours, 1968, on card, each signed, dated and titled in pencil, inscribed artist's proofs, aside from the standard edition of 75, printed to the edges of the full sheets, creasing at the extreme edges of the corners and other minor defects, otherwise in good condition S. 755 x 755 mm. (each) (4)