Object Type
This Great Exhibition souvenir was a lid made by T.J. & J. Mayer for Crosse & Blackwell, of 21, Soho Square, who registered it in 1850 to ensure their competitors did not use the design. The pots for which this lid was made would have contained Crosse & Blackwell's potted meats or anchovy paste. Other firms also made pot lids, the finest being produced between 1850 and 1870.

People
Thomas, Joseph and John Mayer of Dale Hall Pottery, Longport, Burslem, were brothers from a famous Staffordshire family of master potters whose business was established in the 1780s. The Mayer brothers were awarded a prize medal at the Great Exhibition where their stand displayed various designs for meat pots, printed in underglaze colours. Mayers also produced two other views of the Exhibition. They eventually became the second largest manufacturer of colour transfer-printed lids, but made other useful goods as well, and had a thriving export trade with America.

Materials & Making
The firm of F.&R. Pratt & Co. of Lane Delph, Fenton, are thought to have been the earliest exponents of full underglaze colour-printing, though Mayers were quick to follow. An image was produced by engraving at least four different copper printing-plates, one to load with black ink, and the others with a single colour each. The coloured ink from the engraved grooves on the first plate was pressed onto dampened potter's tissue paper, which was in turn applied to the unglazed earthenware and rubbed on with a flannel boss. The tissue was floated off in water, leaving the oily ink on the pottery. After 24 hours' drying time, the next colour was applied on top, and so on, finishing with black or brown, which when accuragtely aligned, completed the image.It was only in the 1840s that suitable printing inks and paper were developed for this process.