Letterpress was the main printing process until the 1970s when it was overtaken by offset lithography and is essentially now a redundant process. It was the printing partner of hot metal typesetting, which has also disappeared from commercial use.
Letterpress is a relief process - that is the printing surface holding the image to be printed is raised above the non-printing background. This surface is inked by rollers and then pressed against the paper to make the impression. Since the background is lower than the printing area, it comes into contact with neither the inking rollers nor the paper and therefore does not print.
In traditional letterpress, all the text is printed from metal type and the illustrations, from letterpress cuts (blocks). These elements are assembled together to create a 'forme' inside a rigid frame (chase) that is placed in the press.
Letterpress is till used in a very specialised way for private press limited-edition books, and short run work such as invitations and duplicate books that can be numbered and perforated at the same time as printing. Converted letterpress machines are also used for foil stamping, embossing, die cutting and creasing.