Flat bed presses consist of horizontal and parallel presses to the screen. The substrate to be printed is fed manually or automatically onto the bed. The squeegee and screen assembly comprises a head, which is lowered onto the table during the actual printing process. A single color of ink is applied to the top of the screen during printing. The head assembly is lifted off the table printed substrate is removed and replaced with new sheet. It is classified as clamshell presses or vertical-lift presses, depending on how the head is lifted off the table.