
Cy Twombly experimented with mezzotints at Universal Limited Art Editions workshop in Long Island, New York, in 1968, around when Robert Motherwell produced his window-like mezzotints there. The press had only recently established an intaglio studio in 1966, but as a result, Lee Bontecou, Helen Frankenthaler, Jasper Johns, and Twombly had all started making intaglio prints before 1967. Frankenthaler would use mezzotint among other techniques in several prints beginning in the 1980s, and even Johns would eventually produce a colorful mezzotint series in 1995.

Note I
Cy Twombly (American, 1928-2011) printed by Donn Steward published by Universal Limited Art Editions (American, founded 1955)

F, from Sketches
Cy Twombly (American, 1928-2011) printed by Donn Steward published by Universal Limited Art Editions (American, founded 1955)

B, from Sketches
Cy Twombly (American, 1928-2011) printed by Donn Steward published by Universal Limited Art Editions (American, founded 1955)