Pattern books were used by merchants and manufacturers in the textile trade. They were not intended to be seen by anyone working outside the industry - some even contained secret breakthrough information not to be seen by rival companies! For merchants they were a means of recording stock and prices, and often included swatches and illustrations to show potential customers. The pattern books used by the manufacturers contain the techniques, recipes and notes recorded by designers and colourists. John Graham’s potted histories of textile mills around Manchester record some of the industry’s big changes. Roller printing was an extremely important development in the production of textiles. Printing by roller helped complicated designs, such as this hunting scene, to be produced in large quantities. It uses just two colours 40, ‘No.3 Purple Paste’ and 313, ’10 Chrome Yellow’. John Wilkinson’s collection helps us imagine the difficult and lengthy work needed to create dyes. Here he illustrates the colour trials and printing processes for cottons and 'delaines', a wool & cotton mix fabric. The two rows of swatches have been calendered, or rolled, and rinsed in different ways. The swatches on the left have been ‘hot watered’, while those on the right have been ‘washed’. The difference in the final colour is very subtle but important.