As did all printing engravers, wood engravers executed their lettering and imagery backwards, so that the printed result would be right-reading. But differently from copperplate and steel engravers, wood engravers worked more like sculptors in that they cut away everything that was not to be part of their design, leaving the parts that were to print standing in high relief. Printing in multiple colors required either differential inking of various parts of the block; or, more usually, multiple woodblocks, one for each part of the overall design to be printed in a separate color. Doing this and then printing in accurate registration was extremely difficult. Wood engravers/printers created sometimes elaborate trade cards to exhibit their skills to potential customers.