A design for a porphyry vase of this campana or 'Borghese' shape was included as no. 18 in the 1799 designs for vases executed by the Court ciseleur Ludvig Rung. This model was particularly favoured at the Älvdalen (Elfdal) porphyry manufactory and also appears in three variants in the 1805 catalogue (Porphyre La Pierre Royale, Paris, 1990, p. 20 and p. 33). This pair of vases is executed in a rare type of porphyry called Bredvad, in colour and figuring close to Egyptian porphyry. It was apparently difficult to find and almost exlusively supplied to the Royal family.