Creamware printers to Josiah Wedgwood by 1763, for example. By 1760 creamware was often enamelled for decoration, using a technique adopted from the early porcelain industry. This consisted of painting overglaze on the ware with pigments made from finely powdered coloured glass and then firing again to fuse the enamel to the ware. The varied enamel colours did not fuse at the same temperature so several firings were generally needed, adding to the expense. There were approximately 130 potteries in North Staffordshire during the 1750s, rising to around 150 by 1763 and employing up to 7,000 people – a large number
Creamware resistance to thermal shock during firing, whilst flint added to the glaze helped prevent crazing. Creamware was first produced some time before 1740. Originally lead powder or galena, mixed with a certain amount of ground calcined flint, was dusted on the ware, which was then given its one and only firing. This early method was unsatisfactory because lead powder produced poisoning among the potters and the grinding of flint stones caused a disease known as potter's rot. Around 1740 a fluid glaze in which the ingredients were mixed and ground in water was invented, possibly by Enoch Booth of Tunstall,