and leave the printed image firmly bonded to the surface. This method could be varied by transferring the oily print onto a ‘glue-bat’ – a slab of flexible gelatine that could be laid on the workbench whilst a globular pot was carefully rolled over it. Glue-bats allowed more subtle engraving techniques to be used. Underglaze transfer printing was also sometimes used, directly onto the porous biscuit body. Transfer-printing was specialist and so generally outsourced in the early years: Sadler & Green of Liverpool were exclusive printers to Josiah Wedgwood by 1763, for example.P Holdway, "Techniques of Transfer-printing on Cream Coloured Earthenware," in Creamware and Pearlware. The Fifth Exhibition from the Northern Ceramic Society. Stoke-on-Trent City Museum & Art Gallery (1986). pp. 20-23 Enamelling 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. Manufacturers and attribution 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 of these potteries would have been producing creamware. Whilst Staffordshire had taken the lead, creamware came to be developed in a number of large potting centres where stoneware was already being produced, eventually replacing stoneware entirely. These included Derbyshire, Liverpool, Yorkshire (including the Leeds pottery) and Swansea. Attribution of pieces to particular factories has always been difficult because virtually no creamware was marked prior to Josiah Wedgwood's manufacture of it in Burslem. At the time manufacturers frequently supplied wares to one another to supplement stocks and ideas were often exchanged or copied. In addition, factories usually sent out their wares to outside specialist enamellers or transfer-printers for decoration – decoration in-house was only gradually adopted. For this reason, several manufacturers usually shared the same decorator or printer and tended to use the same or very similar patterns. Collectors, dealers and curators alike were frustrated in their efforts to ascribe pots to individual factories: it is frequently impossible to do so.Terrence A Lockett, "Problems of Attribution," in Creamware and Pearlware. The Fifth Exhibition from the Northern Ceramic Society. Stoke-on-Trent City Museum & Art