In printing, set-off is the term given to the unwanted transfer of ink from one printed sheet to another. The problem can occur with most types of printing, and is avoided by the use of slipsheets between copies (so any ink transfer occurs onto discardable paper) or anti-set-off spray powder.
The term in offset printing also refers to the unwanted transfer of ink to rollers and friction points throughout the printing press. Ink that is not properly dried or set can build up over time and cause marking on the finished product.
Additionally, some offset printing applications add moisture back into the paper template after an offset heat set dryer. Water that does not have enough hardness will break down the calcium carbonate in the paper and cause build-up or set-off on later components of the press.
In computing, a printer is a peripheral machine which makes a durable representation of graphics or text, usually on paper. While most output is human-readable, bar code printers are an example of an expanded use for printers. Different types of printers include 3D printers, inkjet printers, laser printers, and thermal printers.
Lithography is a planographic method of printing originally based on the immiscibility of oil and water. The printing is from a stone or a metal plate with a smooth surface. It was invented in 1796 by the German author and actor Alois Senefelder and was initially used mostly for musical scores and maps. Lithography can be used to print text or images onto paper or other suitable material. A lithograph is something printed by lithography, but this term is only used for fine art prints and some other, mostly older, types of printed matter, not for those made by modern commercial lithography.
A mimeograph machine was a low-cost duplicating machine that worked by forcing ink through a stencil onto paper. The process was called mimeography, and a copy made by the process was a mimeograph.
In publishing, printers are both companies providing printing services and individuals who directly operate printing presses.
Screen printing is a printing technique where a mesh is used to transfer ink onto a substrate, except in areas made impermeable to the ink by a blocking stencil. A blade or squeegee is moved across the screen in a "flood stroke" to fill the open mesh apertures with ink, and a reverse stroke then causes the screen to touch the substrate momentarily along a line of contact. This causes the ink to wet the substrate and be pulled out of the mesh apertures as the screen springs back after the blade has passed. One colour is printed at a time, so several screens can be used to produce a multi-coloured image or design.
Printmaking is the process of creating artworks by printing, normally on paper, but also on fabric, wood, metal, and other surfaces. "Traditional printmaking" normally covers only the process of creating prints using a hand processed technique, rather than a photographic reproduction of a visual artwork which would be printed using an electronic machine ; however, there is some cross-over between traditional and digital printmaking, including risograph.
Printing is a process for mass reproducing text and images using a master form or template. The earliest non-paper products involving printing include cylinder seals and objects such as the Cyrus Cylinder and the Cylinders of Nabonidus. The earliest known form of printing evolved from ink rubbings made on paper or cloth from texts on stone tablets, used during the sixth century. Printing by pressing an inked image onto paper appeared later that century. Later developments in printing technology include the movable type invented by Bi Sheng around 1040 and the printing press invented by Johannes Gutenberg in the 15th century. The technology of printing played a key role in the development of the Renaissance and the Scientific Revolution and laid the material basis for the modern knowledge-based economy and the spread of learning to the masses.
Inkjet printing is a type of computer printing that recreates a digital image by propelling droplets of ink onto paper and plastic substrates. Inkjet printers were the most commonly used type of printer in 2008, and range from small inexpensive consumer models to expensive professional machines. By 2019, laser printers outsold inkjet printers by nearly a 2:1 ratio, 9.6% vs 5.1% of all computer peripherals.
Dye-sublimation printing is a term that covers several distinct digital computer printing techniques that involve using heat to transfer dye onto a substrate.
Flexography is a form of printing process which utilizes a flexible relief plate. It is essentially a modern version of letterpress, evolved with high speed rotary functionality, which can be used for printing on almost any type of substrate, including plastic, metallic films, cellophane, and paper. It is widely used for printing on the non-porous substrates required for various types of food packaging.
Print or printing may also refer to:
Giclée describes digital prints intended as fine art and produced by inkjet printers. The term is a neologism, ultimately derived from the French word gicleur, coined in 1991 by printmaker Jack Duganne. The name was originally applied to fine art prints created on a modified Iris printer in a process invented in the late 1980s. It has since been used widely to mean any fine-art printing, usually archival, printed by inkjet. It is often used by artists, galleries, and print shops for their high quality printing, but is also used generically for art printing of any quality.
Xerography is a dry photocopying technique. Originally called electrophotography, it was renamed xerography—from the Greek roots ξηρόςxeros, meaning "dry" and -γραφία-graphia, meaning "writing"—to emphasize that unlike reproduction techniques then in use such as cyanotype, the process of xerography used no liquid chemicals.
An inkometer is a specialized measuring instrument used by the printing industry to measure the "tack" (adhesiveness) of an ink with the roller system on an offset press. The importance of tack is that it is not so excessive that it doesn't allow effective transfer from the rollers to the plate and then to the blanket and onto the substrate being printed. Inks can also be tack "graded" in descending sequence to allow for better trapping of one color over another. Inks with too much tack can cause the surface of the paper to pick off and interfere with transfer on subsequent printing units and copies.
Offset printing is a common printing technique in which the inked image is transferred from a plate to a rubber blanket and then to the printing surface. When used in combination with the lithographic process, which is based on the repulsion of oil and water, the offset technique employs a flat (planographic) image carrier. Ink rollers transfer ink to the image areas of the image carrier, while a water roller applies a water-based film to the non-image areas.
Letterpress printing is a technique of relief printing for producing many copies by repeated direct impression of an inked, raised surface against individual sheets of paper or a continuous roll of paper. A worker composes and locks movable type into the "bed" or "chase" of a press, inks it, and presses paper against it to transfer the ink from the type, which creates an impression on the paper.
Rotogravure is a type of intaglio printing process, which involves engraving the image onto an image carrier. In gravure printing, the image is engraved onto a cylinder because, like offset printing and flexography, it uses a rotary printing press.
In printing, anti-set-off spray powder is used to make an air gap between printed sheets of paper. This enables the ink to dry naturally and therefore avoid the unwanted transfer of ink from one printed sheet to another. The problem can occur with most types of printing.
A variety of tests are used to determine ink and paper and paperboard quality, and to measure their interactions. They are necessary to balance print quality, cost, and wear on the press. Some of the important paper and ink tests are listed here:
The Washington–Franklin Issues are a series of definitive U.S. Postage stamps depicting George Washington and Benjamin Franklin, issued by the U.S. Post Office between 1908 and 1922. The distinctive feature of this issue is that it employs only two engraved heads set in ovals—Washington and Franklin in full profile—and replicates one or another of these portraits on every stamp denomination in the series. This is a significant departure from previous definitive issues, which had featured pantheons of famous Americans, with each portrait-image confined to a single denomination. At the same time, this break with the recent past represented a return to origins. Washington and Franklin, after all, had appeared on the first two American stamps, issued in 1847, and during the next fifteen years, each of the eight stamp denominations available featured either Washington or Franklin.