Editing Spode (section)

=== Underglaze blue transfer printing ===
Josiah Spode I is credited<ref>Hayden 1925, p. viii.</ref> with the introduction of underglaze blue transfer printing on earthenware in 1783–84. The [[Worcester porcelain|Worcester]] and [[Caughley porcelain|Caughley]] factories had commenced transfer printing underglaze and over glaze on porcelain in the early 1750s, and from 1756 overglaze printing was also applied to earthenware and stoneware. The processes for underglaze and overglaze decoration were very different. Overglaze "bat printing" on earthenware was a fairly straightforward process, and designs in a range of colours including black, red and lilac were produced. Underglaze "hot-press" printing was limited to the colours that would withstand the subsequent glaze firing, and a rich blue was the predominant colour.

To adapt the process from the production of small porcelain teaware to larger earthenware dinnerware required the creation of more flexible paper to transmit the designs from the engraved copper plate to the biscuit earthenware body, and the development of a glaze recipe that brought the colour of the black-blue cobalt print to a brilliant perfection. When Spode employed the skilled engraver Thomas Lucas and printer James Richard, both of the Caughley factory, in 1783 he was able to introduce high quality blue printed earthenware to the market. [[Thomas Minton]], another Caughley-trained engraver, also supplied copper plates to Spode until he opened his own factory in Stoke-on-Trent in 1796.
<ref>Hayden 1925, 46–53.</ref>

This method involved the [[engraving]] of a design on a copper plate, which was then printed onto gummed tissue.<ref>Robert Copeland, ''Blue and white transfer printed pottery'' (Osprey publishing (Shire series), 2000), p. 11 ff. [https://books.google.com/books?id=koeTCVxpb5sC&dq=engraved+blue+and+white+transfers&pg=PA11]</ref> The colour paste was worked into the cut areas of the copper plate and wiped from the uncut surfaces, and then printed by passing through rollers. These designs, including edge-patterns which had to be manipulated in sections, were cut out using scissors and applied to the biscuit-fired ware (using a white fabric), itself prepared with a gum solution. The tissue was then floated off in water, leaving the pattern adhering to the plate. This was then dipped in the glaze and returned to the kiln for the [[glost firing]]. Blue underglaze transfer became a standard feature of Staffordshire pottery. Spode also used on-glaze transfers for other wares. The well-known Spode blue-and-white dinner services with engraved sporting scenes and Italian views were developed under Josiah Spode the younger, but continued to be reproduced into much later times.