14 evidently a very capable and diligent painter and hence undoubtedly a threat to Höroldt’s undertaking. This may have been one of the reasons for firing him. New information gleaned on Ripp’s time at Meissen has made it necessary to re-assess the datings of underglaze-blue patterns from the early years, and to whom they are to be attributed.5 Amongst the earliest documented examples of underglaze decoration in cobalt blue from Meissen are six saucer-dishes with nautical motifs in the Delft style that have been attributed to Ripp despite being dated to a period during which he definitely was not working in Höroldt’s workshop.6 Lutz Miedtank accordingly posits that the saucer-dishes may have been decorated during Ripp’s first spell at Meissen from September to November 1720. If true, this would indicate very early adoption of the blue Caduceus or whip mark (fig. 1). If these six plates were made in 1721 or early 1722, they may have been the work of blue-painter Johann Christoph Horn (1692 –1760), who is listed as a painter in Höroldt’s workshop in early 1721 after Ripp departed for Zerbst at the end of November 1720.7 The records Köhler kept between 1720 –1722 of his formulae for blue8 are amongst the oldest of their kind and contain a wealth of detail of both historical and technical interest. He lists three paste recipes for “calcareous porcelain”, for instance, incorporating Schnorr’s earth (kaolin from Aue), Colditz clay and alabaster. Köhler was likewise the first to note the use of “stone” as a fluxing agent. His records contain the earliest known reference to the use of feldspar, moreover.9 Köhler tested 20 different cobalt ores from a number of pits in around 1720, with greatly varying degrees of success. He was able to conclude following a great deal of experimentation that the best underglaze blue is achieved on a feldspathic ceramic body. Bolstered by this insight, he recommended admixing earth and kaolinic sand – and that was new. Stöltzel was busy experimenting, too, however. He jotted down diverse paste and glaze formulations he had already trialled in Vienna in his notebook10. By around 1732, he was strongly advocating feldspathic formulations as being the most suitable, partly owing to the workability of the paste. He detailed three procedures for preparing a blue underglaze colour: a) producing cobalt carbonate by chemical reaction, b) smelting cobalt ore, knocking it out and grinding it into coloured powder and c) producing underglaze blue by roasting cobalt ore.11 Stöltzel and Köhler were rivals and each endeavoured in his own way to make progress in perfecting underglaze blue. They were spurred on by a reward of 1,000 Thalers – a minor fortune at the time – offered
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