See J.D. van Dam, Dated Dutch Delftware, Zwolle, 1991, ill. p. 11 for the side view and p. 10 for a discussion (op.cit.) 'On rare occasions a painter from outside or an amateur would have decorated Delftware. The side view of the tomb of William the Silent by Hendrick de Keyzer in Delft is just such an exception, painted by an amateur Isaac Junius, baptised in Haarlem on 29 May 1616 before becoming sheriff of beide Catwijcken en 't Zandt, he probably never painted Delftware professionally. The size of the plaque was determined by the dimensions of the engraving by Cornelis Danckerts from which Junius made a pricked drawing. The plaque lay horizontally during firing, whereas most pieces were placed upright....The plaque became warped in the kiln.... This piece and an undated plaque with the frontal view of the tomb, which is also in the collection of the Rijksmuseum, form a pair. It almost goes without saying that such an exceptional piece, painted by an amateur, was dated'.
See J. D. van Dam, Delffse Porceleyne, Zwolle, 2004, p. 44 ill. 17 for the frontal view and M. van Aken-Fehmers and L. Schledorn, Delfts aardewerk, Geschiedenis van een nationaal product, Zwolle, 1999, p. 26 ill. 1 for the side view, in the Gemeentemusea Delft, Museum Huis Lambert van Meenten and p. 28 for a discussion referring to an inventory report of 1661, most probably of the pottery Het Gecroond Porceleyn, in which such a pair is described: (op.cit) '2 porsseleine stucjes van het graff van prins [Willem van Oranje] in de Nieuwe Kerk met ebbe lijsten' (Two 'porcelain' pieces from the tomb of prince [William of Orange] in the Nieuwe Kerk with ebony frames). The Rijksmuseum pair is currently displayed in the temporary Masterpieces exhibition, which is organised during the renovation of the Rijksmuseum, Amsterdam.