Letterpress Printing - Letterpress Printers Information
Letterpress is one of the oldest forms of printing. It involves printing text with movable
type, in which the raised face of the type is inked and then pressed against a
smooth substrate to achieve the desired image. The
letterpress process is referred to as a "relief" process because the
printed image is produced from a plate in which the image area is slightly
raised above the non-image surface of the plate.
Since most letterpress equipment produces only one color
at a time, printing with more than one color can be challenging. The inking
system on letterpress equipment is less precise than on offset presses, which
can create problems with some graphics. However, an experienced printer can
overcome many of these problems.
Equipment Used in Letterpress Printing
There are three different types of letterpress printing devices in use today:
Platen, Flat-Bed, and Rotary presses.
Rotary Letterpress Printing - There are two types of rotary letterpresses,
sheet-fed and web-fed. On a rotary sheet fed press, the plate is mounted on a
cylinder where a roller system applies ink to the raised area of the plate. The
paper passes between the plate cylinder and an impression cylinder where the
resulting squeeze between the two cylinders produces the printed impression on
the paper. Web-fed rotary letterpress presses are used primarily for printing
newspapers. These presses utilize a plate and impression cylinder, but instead
of individual sheets passing between the two cylinders, the paper is a
continuous web unwound from a large roll. Typically, they can print up to four
pages across the web; however, some of the new presses can print up to six pages
across a 90-inch web. Rotary letterpress is also used for long-run commercial,
packaging, book, and magazine printing.
Platen-type Letterpress Printing - A platen press is made up of two flat surfaces
called the bed and the platen. The platen provides a smooth backing for the
substrate that is to be printed. The raised plate (image to be printed) is
locked onto a flat surface. The plate is inked, the substrate is then placed on
another flat surface called the bed and pressed against the inked plate
producing the impression. Platen printing is typically used for short runs such
as invitations, name cards, and stationary. Larger platen presses are used for
die-cutting and embossing.
Flat-Bed Cylinder Letterpress Printing - Flat-bed cylinder presses use either
vertical or horizontal beds. The plate is locked to a bed which passes over an
inking roller and then against the substrate. The substrate passes around an
impression cylinder on its way from the feed stack to the delivery stack. The
presses can print either one or two-color impressions. Flat-bed cylinder presses
operate very slowly, having a production rate of not more than 5,000 impressions
per hour.
Letterpress printing has since been replaced by offset
printing and other processes, but it is still used for some newspapers, books,
and limited edition prints. Letterpress printing may also be used for producing
small quantities of business cards, letterhead, and posters.
Resources:
Printers National
Environmental Assistance Center
International
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