Rotograph apparently dedicated the 29000's to this group of art cards.  Featuring copies of both religious and secular art, they were printed by Stengel and offer outstanding examples of the color lithography being done at the time.  Many (perhaps all) of these also appear as Stengel cards bearing Stengel's own imprint, and cards with the imprint of both companies (but the same series #) can be found.  The Rotograph versions are udb, while all of the Stengels which I have are db, suggesting that Stengel took over or continued the line.

        The cards are on a heavy stock with the print running to the edge on three sides of the card.  The remaining side carries space where is printed title of the work, painter, and location of the work.  In some cases, the artwork takes up the entire card, with identification OB.