What Is Letterpress Printing?

Letterpress printing is a kind of relief printing. By repeatedly pressing an inked, raised surface against sheets or a continuous roll of paper using a printing press, the method enables the production of many copies.

A worker composes and locks moveable type into the “bed” or “chase” of a press, inks it, and presses paper toward it to send the ink from the type onto the paper, leaving an impression.

The letterpress encompasses additional printmaking methods with printing presses, like wood prints, photo-etched zinc “cuts” (plates), and lino blocks, which can be used with metal or wood types in a single process as type and block stereotypes and electrotypes.

Combining moveable type with slugs cast via hot metal typesetting with some letterpress systems is also feasible.

In principle, anything “type high” creates a layer precisely 0.918 in. thick between the bed, and the paper may be printed using letterpress.

Letterpress printing was the usual form of printing text from its discovery by Johannes Gutenberg in the mid-15th century through the 19th century. It remained in extensive usage for books and other applications until the second half of the 20th century.

Letterpress printing remained the dominant way of printing and conveying information until the 20th century when offset print was invented, overtaking its role in producing books and newspapers. More lately, letterpress printing has witnessed a rebirth in an artisanal form.

How does it work?

Letterpress printing utilizes printing plates, which are perhaps the most important component because they are responsible for transferring ink to the item to be printed. Using a film processor, the visuals are converted to litho film before being used to create printing plates.

The litho film photography is then placed over the plates, which are placed in the platemaker machine and coated with a vacuum sheet.

The platemaker machine then exposes the printing plates and litho film to UV illumination to transfer the graphics to the printing plates. The plates are then washed with water before being cooled. Finally, they are re-exposed to UV radiation to harden and stabilize them for the printing process.

Since the printing plates can only contain one color at a time, letterpress printing typically only produces one color. Therefore, if the images contain more than one color, the printing plates must be switched and the printed paper cooled.

The system lacks a cooling mechanism; thus, users generally have to wait to cool off. It generally significantly delays the production process, so it is often printed in a single color.

Letterpress printing may utilize both CMYK and Pantone colors. However, since the colors are added one time, Pantone colors are typically used.

The ink is either put directly to the rollers or to a flat iron plate, which the roller then rolls over to pick up. The rollers must ensure that there is always sufficient ink for printing by rolling over the printing plate after it has produced one object.

For the process to operate, the printing plate is pushed onto the items to be printed. In between presses, rollers run over the printing plate to add additional ink to ensure that the correct amount of ink is applied to the object. After the ink has been applied, the piece is ready for use after it has cooled down.

Letterpress printing frequently produces a debossing effect, so the letters or pictures are pushed into the items.