This original lithograph, signed and inscribed, is number 18 out of an edition of 60 made by the artist for The Curwen Studio in 1975, four years after the lithograph Delos (1971) edition 9/60, also from the Eric and Jean Cass collection and now in Brighton Art Gallery, but also forms one of 9 screenprints from The Aegean Suite (sets at Tate and The Pier Arts Centre, Stromness, edition not numbered). They were purchased by the Cass's together and catalogued (in 2003, possibly erroneously and therefore mistitled) as if a pair. An identical motif, called December Forms (1970) forms part of a screenprint series of 12, not numbered (sets at Tate and The Pier Arts Centre, Stromness) called Opposing Forms.