When ink is applied to a raised surface and paper is pressed against the inked surface, the ink is transferred to the paper, Figure 1-2. Relief and letterpress are terms that describe printing methods that use this principle. The rubber stamp is a device that prints by the relief or letterpress method. It transfers ink from a raised surface to paper. Typewriter elements, also print in this way.
Figure 1-2. Relief or letterpress printing. The lowered sruface does not print because it doesn't come in contact with the ink or the paper.
Foundry type, Monotype, Linotype, and Ludlow are used by the letterpress printer to trasfer letters and numbers to paper, Figure 1-3. The plates of wood cut, wood engraving, linoleum block, and photoengraving can also be used in letterpress printing. Their raised surfaces can print photoengraving and illustrations as well as letters and numbers.
Relief or letterpress printing is the oldest printing method. Today a wide variety of letterpress plates are used on several types of presses to print a rich and varied assortment of products including nespapers, books, and magazines.
IMAGE REVERSAL. As you can see, the principle of printing from a raised surface is not difficult to understand. There is one problem to consider, however. Look at Figure 1-2 again. Note that the shape of the raised surface that printed the letter P on paper is "wrong reading" or backwards. The raised surface was purposely prepared this way so that it would print a "right reading" image on the paper.