A similar example from the Collection of Mr. and Mrs. Ronald Billington was sold Christie's, London, 27th February 1989, lot 22. An octagonal example of this type is illustrated in Leslie B. Grigsby, The Longridge Collection of English Slipware and Delftware, London, 2000, p. 460, no. D411. The combination of a shield form with an oval cartouche and a strapwork label is extremely unusual; see J.K. Crellin, Medical Ceramics in the Wellcome Institute, London, 1969, pp. 143-150, Figs. 263-278 and col. pl. 3.