The major development in 19^th century printing, and one which was to have far-reaching effects on jobbing printing, was that of lithography, discovered by Senefelder in c. 1798 (the exact date has not been established with certainty). The task of advertisers such as James Allan was to make the process financially attractive. The transfer of images from copper plates meant that tradesmen did not have to go to the expense of commissioning an original drawing on lithographic stone. Allan continued, however, to print in letterpress and copper-plate.