The following are from Elaine Lustig Cohen and Ellen Lupton's book
Letters from the Avant Garde: Modern Graphic Design, most of which came from Elaine Lustig Cohen's personal collection. Elaine Lustig Cohen was an excellent artist/designer [more on that in a later post] who was married to the great Alvin Lustig. She and her second husband, author/publisher Arthur Cohen, began collecting letterhead in the 1970s for their
Ex Libris gallery, but the letters rarely sold. Although collectors at the time tended to view them as unimportant, they offer an unique and personal perspective into many of the most important artistic movements of the early twentieth century.

Kurt Schwitters, Merz Werbezentrale envelope. Hanover, 1924

Josef Peeters, Het Overzicht postcard. Antwerp, 1923

Joost Schmidt, Das Bauhaus in Dessau postcard. Dessau, 1925-26

Johannes Baader and Raoul Hausmann, Club Dada postcard. Berlin, c. 1919

Herbert Bayer, Ernst Kraus Glasmaler Weimar. Weimar, 1924 (Collection W Michael Sheehe, New York)

FT Martinetti, drawing by Giacomo Ball, Movimento Futurista. Rome, 1939

Fortunato Depero, Depero. Italy (Trentino), c. 1927 (Collection Getty Center for the History of Art and the Humanities, Santa Monica)

El Lissitzky. Moscow, 1924

El Lissitzky, VescObjectGegenstand. Berlin, 1922 (from the collection of Hans Berndt, Germany)

E McKnight Kauffer, Lumium Limited. London, 1935 (Collection Cooper-Hewitt, Nat. Design Museum, Smithsonian Institution)

Bruno Munari, Mazzotti. Italy, 1934

Benjamin Péret. Paris (Collection W Michael Sheehe, New York)

Anonymous, Fernando Cervelli. Rome, 1932 (Collection Getty Center for the History of Arts and the Humanities, Santa Monica)

Anonymous, Cause Le Surréalism (a Surrealist association). Paris, 1940s

Alexander Rodchenko, Dobrolet State Merchant Air Service. Moscow, 1923
see full post
here