Letterpress is a relief-type printmaking process, meaning that ink adheres to raised surfaces--like a rubber stamp--before the printmaker applies paper on top of the inked letterpress blocks and runs the two through a press. Letterpress is an arduous and time-consuming process, as the operator lays out text blocks letter-by-letter before having a full plate from which to print a page.
Though printers and newspaper used letterpress for centuries--to reproduce newspapers, books, pamphlets and posters--faster and more efficient technologies have pushed letterpress out of mass use. However, many artists and printmakers still use letterpress for craft and artistic projects, particularly for printing upscale stationary and artist's books. Letterpress techniques are still taught at a number of schools and group studios, including New York's Center for the Book Arts and and Seattle's Black Rock Press.
Screenprinting involves a very differ ent process than letterpress. With screenprinting, ink is pushed through a taut silk screen and then printed on a sheet of paper. To make an image, screenprinters stretch a silk screen over a frame, and then block off the areas which they don't want ink to go through (this can be done using a gel that hardens).
Andy Warhol popularized screen printing in the 1960s with his prints of Marilyn Monroe, advertising logos, Jackie Kennedy and press photographs. Screenprinters now use the form in various ways, from fine art prints to posters to T-shirts. It costs little, and the screens and prints can be assembled and made at home.