Cover by an unknown designer for the 1972 Bantam Books paperback edition of The Exorcist by William Peter Blatty. Cover photograph by Frederick Cantor, as also featured on the 1971 Harper & Row first edition. Please note: cover creases and edge wear are the result of age and are not part of the cover design.
The front panel, back panel and spine feature the novel’s title, author’s name and additional text set in Gemini. The back panel also features what appears to be Times New Roman Extra Bold along with review snippets set in Caledonia. Publisher’s text on the top left of the front panel and along spine is also set in Caledonia.
The use of Gemini for the titling on this paperback edition may have had a direct influence on the type used on the one sheet poster for the 1973 film adaptation. The paperback was published in July, 1972, whilst the film was in production, with photography set to begin in mid-August, 1972. An early poster maquette for the film, purportedly from 1972, seems to support this idea with its titling closely resembling that of the paperback.
[More info on ISFDB]