Letterpress PrintingThe unique patterns on the ends of your fingers, should they ever be printed, would be transferred to a sheet of paper by the "relief" method. The raised patterns of skin get coated with ink while the skin in the valleys between the patterns remain uninked; then the ink on the ridges of the patterns is pressed onto the paper. The relief method is the basis of letterpress printing.
From the middle of the 15th century until only twenty years ago, letterpress was the preferred (almost, the only) method of reproducing the thoughts and ideas of scholars, or the stories of heroes and lovers. Until the beginning of this century every single word was set by hand: every letter of every word, and even the spaces in between! The process of setting type by hand is too detailed to cover here except to say that the type is "composed" -- picked up one letter at a time, in order, and placed into a "stick" -- a wood or metal tray held in one hand to store the words as they are built into lines of type, before being made up into pages.
A paragraph, or a page, consists of a number of lines of a fixed width made up of tall rectangular blocks of lead, with the characters raised above the surface on top of the blocks. This page is made up on a "turtle" -- a smooth-topped table of metal or marble -- and the sides surrounded by a metal frame called a "chase". The space between the page and the chase walls is filled with wooden or metal "furniture" which is lower than "type height" so as not to pick up any ink. The final spaces are filled with expandable "quoins" which, when tightened, lock all the type and furniture safely within the chase, (now called a "forme") and able to be carried to the press.
The image on the right shows a platen job press the way a printer would face it. The wooden feed board is swung out to the right, with the delivery board in the middle, about belt height. On the left is the flywheel, used both to start and maintain the momentum of the press during the actual printing. At the top of the picture is the inking disk which rotates slowly during the cycle. Hidden from view, between the delivery board and the ink disk, is where the action takes place.
The forme is locked vertically into one half of the press, while the paper to be printed is placed into position on the opposite half; the two halves being hinged at the bottom, like a V. Also attached to one half are the roller carrying arms which hold a series of rubber rollers, allowing them to roll over the face of the forme. During the printing cycle the rollers pick up ink from the inking disk then roll down over the type, depositing a thin film of ink on the tops of the characters. They then continue to roll out of the way so the the two halves can come together, tranferring the ink from the type to the paper. To complete the cycle, the two halves open as the rollers travel back up the forme and onto the inking plate where they pick up a fresh supply for the next cycle. When the two halves are wide apart, the pressman removes the printed sheet and replaces it with a fresh one and begins the next cycle.
The most distinctive quality of letterpress printing, and by which one can usually distinguish it from offset printing, is that the printed image (whether type or illustration) is actually impressed into the paper through the pressure of the press. Not only can you often see or even feel the impression on the back of the paper but, if the lighting is correct, you can see a certain "sparkle" around the edges of the type. That is, because the type is impressed into the paper, the light causes a highlight around one edge of the impression while a shadow appears around the opposite edge. It is this sparkle which gives life to a page of letterpress-printed type: a quality missing from offset- or otherwise-printed pages, and even from digital pages.
You will find a list letterpress sites on the links page.
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