"Green & Yellow" is titled and numbered "45" in sepia ink on the verso. Hobart numbered his monotypes sequentially.
A work similar to this, "Indian Summer" is illustrated in color in the book 'Singular Impressions: The Monotype in America', Joann Moser, Smithsonian Press, 1997; figure 103, page 104. Moser's comments also apply to "Green & Yellow":
"Hobart's serious involvement with monotypes is indicated by the fact that he signed all of them and gave most impressions an individual title, inscribed in pencil beneath the image. Ranging from exhuberant, impressionistic compositions....to softer, more atmospheric idylls such as (in this case, "Green and Yellow"), printed from a canvas surface..."
Clark Hobart was part of a group of California printmakers who were working in monotype in the early 20th century but he and Xavier Martinez were the only artists to exhibit them at the 1915 Panama Pacific Exposition in San Francisco, with 12 monotypes shown by Hobart. He won a Silver Medal for these works.
Hobart discussed his printmaking: "A 'monotype' is perhaps the most severe test of and artist's creative skill. It is painted on copper in oil & while damp is transferred by means of a (clothes) wringer to the paper, which is its final form.
The composition is conceived & painted without the change of a a single stroke in the limited time to make possible the transfer to the paper. Should a stroke be added on top of the first stroke it would be covered by the first stroke in the transfer."