Letterpress printing is a term for printing text with movable type, in which the raised surface of the type is inked and then pressed against a smooth substance to obtain an image in reverse. In addition to the direct impression of inked movable type onto paper or another receptive surface, the term letterpress can also refer to the direct impression of inked media such as zinc "cuts" (plates) or linoleum blocks onto a receptive surface.
Early Chinese woodblock printing used characters or images carved in relief from before 750AD, and this form of printing was widespread throughout Eurasia as a means of printing patterns on textiles. Printing of images, first on cloth, then from about 1400 on paper was practised in Europe. In the 1400s, Johann Gutenberg (among others) is credited with the invention of movable type printing from individually-cast, reusable letters set together in a forme (frame). This had previously been invented in Asia, but the two inventions were probably not connected. He also invented a wooden printing-press, based on the existent wine press, where the type surface was inked and paper laid carefully on top by hand, then slid under a padded surface and pressure applied from above by a large threaded screw. With the advent of industrial mechanisation, the inking was carried out by rollers which would pass over the face of the type and move out of the way onto a separate ink-bed where they would pick up a fresh film of ink for the following sheet. Meanwhile a sheet of paper was slid against a hinged platen (see image) which was then rapidly pressed onto the type and swung back again to have the sheet removed and the next sheet inserted (during which operation the now freshly-inked rollers would run over the type again). In a fully-automated 20th century press, the paper was fed and removed by vacuum sucker grips.
Rotary presses were used for high-speed work. In the oscillating press, the forme slid under a drum around which each sheet of paper got wrapped for the impression, sliding back under the inking rollers while the paper was removed and a new sheet inserted. In a newspaper press, a papier-mâché mixture (flong) was used to make a mould of the entire forme of type, then dried and bent, and a curved metal plate cast against it. The plates were clipped to a rotating drum, and could thus print against a continuous reel of paper at the enormously high speeds required for overnight newspaper production.
The invention of Ultra-Violet curing inks has helped keep rotary letterpress alive in areas like self-adhesive labels. There is also still a large amount of flexographic printing, a similar process, which uses rubber plates to print on curved or awkward surfaces, and a lesser amount of relief printing from huge wooden letters for lower-quality poster work.
Rotary letterpress machine are still used on a wide scale for printing of self-adhesive and Non self-adhesive labels, tube laminate, cup stock etc. The printing quality achieved by the modern letterpress machines with UV curing is on par with flexo presses. Several converters the world over still swear by these rugged machines. It is more convenient and user friendly then a flexo press. Water wash photopolymer plates are used which are as good as any solvent washed flexo plate. Nowadays even CtP plates are available making it a full fledged modern printing process. As there is no Anilox roller in the process, the makeready time also goes down when compared to a flexo press. Inking is controlled by keys very much similar to an offset press. UV inks for letterpress are in paste form unlike flexo. There are various manufacturers of UV rotary letterpress machines viz. Taiyo Kikai, KoPack, Gallus etc. which offer various other online functions like Hot/ Cold foil stamping, rotary die cutting, Flatbed die cutting, Sheeting, Rotary Screen Printing, Adhesive side printing,InkJet numbering etc. The Cental Impression presses are more popular then inline ones due to their ease of registration and simple design. Printing of up to 9 colours plus varnish is possible with various online converting processes.
A small amount of high-quality art and hobby letterpress printing remains — fine letterpress work is crisper than offset litho because of its impression into the paper, giving greater visual definition to the type and artwork. Today, many of these small letterpress shops survive by printing fine editions of books or by printing upscale invitations and stationery, often using presses that require the press operator to feed paper one sheet at a time by hand. They are just as likely to use old printing methods as new, for instance by printing photopolymer plates (used in modern rotary letterpress) on restored 19th century presses.
The process requires a high degree of craftsmanship, but in the right hands, letterpress excels at fine typography. It is used by many small presses that produce fine handmade limited-edition books, artists' books, and high-end ephemera such as greeting cards and broadsides.
To bring out the best attributes of letterpress, printers need to understand the capabilities and advantages of what can be a very unforgiving medium. For instance, since most letterpress equipment prints only one color at a time (unlike presses for offset printing which often use four-color process printing), printing multiple colors can be challenging. The inking system on letterpress equipment is less precise than on offset presses, which can pose problems with some graphics: detailed, white (or "knocked out") areas, such as small, serif type, or very fine halftone, surrounded by fields of color, can fill in with ink and lose definition. However, a skilled printer can overcome most of these problems.
While less common in contemporary letterpress printing, it is possible to print halftoned photographs, via photopolymer plates, on letterpress equipment. However, letterpress printing's strengths are crisp lines, patterns and other graphics, and typography.
Letterpress publishing has recently undergone a revival in the USA, Canada and the UK, under the general banner of the 'Small Press Movement'. Discarded by commercial print shops, affordable letterpress printing presses (in particular, Vandercook cylinder proof presses and Chandler & Price platen presses. In the UK there is particular affection for the Halifax built by Arab) became available to artisans throughout the country. The movement has been helped by the emergence of a number of organizations that teach letterpress such as Columbia College Chicago's Center for Book & Paper Arts, New York's Center for Book Arts, Studio on the Square and The Arm NYC, the San Francisco Center for the Book, Bookworks, Seattle's School of Visual Concepts, Black Rock Press and the Minnesota Center for Book Arts.
Several dozen colleges and universities around the United States have either begun or re-activated programs teaching letterpress printing in fully-equipped facilities. In many cases these letterpress shops are affiliated with the college's library or art department, in others they may be independent, student-run operations, or extracurricular activities sponsored by the college. Many are included in degree programs. More information can be found on the College & University Letterpress Printers' Association (CULPA) website CULPA was founded in 2006 by Abigail Uhteg at the Maryland Institute College of Art in order to help these schools stay connected and share resources.
The current renaissance of letterpress printing has created a crop of hobby press shops that are owner operated and driven by a love of the craft. Several larger printers have added an environmental component to the venerable art by using only wind power to drive their presses and plant equipment.
In London, St Bride's Printing Library houses a large collection of letterpress information in its collection of 50,000 books. All the classic works on printing technique, visual style, typography, graphic design, calligraphy and more. This is one of the worlds foremost collections and is located off Fleet Street in the heart of London's old printing and publishing district. In addition regular talks, conferences, exhibitions and demonstrations take place.
Central St Martin's College and London College of Communication run short courses in letterpress as well as offering these facilities as part of their Graphic Design Degree Courses.
The individual letterforms used to compose a block of text for printing were designed and fabricated by a punchcutter.