Editing Printing (section)

==Conventional printing technology==
All printing process are concerned with two kinds of areas on the final output:
# Image area (printing areas)
# Non-image area (non-printing areas)

After the information has been prepared for production (the [[prepress]] step), each printing process has definitive means of separating the image from the non-image areas.

Conventional printing has four types of process:
# [[Planographic printing|Planographics]], in which the printing and non-printing areas are on the same plane surface and the difference between them is maintained chemically or by physical properties, the examples are: [[Offset printing|offset]] [[lithography]], [[collotype]], and screenless printing.
# [[Relief printing|Relief]], in which the printing areas are on a plane surface and the non printing areas are below the surface, examples: flexography and letterpress.
# [[Intaglio (printmaking)|Intaglio]], in which the non-printing areas are on a plane surface and the printing area are etched or engraved below the surface, examples: steel die engraving, [[gravure]], [[etching]], [[Collagraphy|collagraph]].
# Porous or [[Stencil printing|Stencil]], in which the printing areas are on fine mesh screens through which ink can penetrate, and the non-printing areas are a stencil over the screen to block the flow of ink in those areas, examples: [[screen printing]], [[stencil duplicator]], [[risograph]].

===Crop marks===
To print an image without a blank area around the image, the non-printing areas must be trimmed after printing. Crop marks can be used to show the printer where the printing area ends, and the non-printing area begins.<ref>{{cite web |title=What are crop marks and why would you want to print them? |date=February 9, 2011 |author=Bob deLaubenfels |publisher=[[Microsoft]] |url=https://www.microsoft.com/en-us/microsoft-365/blog/2011/02/09/what-are-crop-marks-and-why-would-you-want-to-print-them/ |archive-url=https://web.archive.org/web/20220424170929/https://www.microsoft.com/en-us/microsoft-365/blog/2011/02/09/what-are-crop-marks-and-why-would-you-want-to-print-them/ |archive-date=April 24, 2022}}</ref> The part of the image which is trimmed off is called [[Bleed (printing)|bleed]].

===Letterpress===
[[File:Commercial. Le Samedi BAnQ P48S1P03551.jpg|thumb|Miehle press printing Le Samedi journal. [[Montreal]], 1939.]]
{{Main|Letterpress printing}}
Letterpress printing is a technique of [[relief printing]]. A worker composes and locks [[movable type]] into the bed of a press, [[ink]]s it, and presses paper against it to transfer the ink from the type which creates an impression on the paper. 
There is different paper for different works the quality of paper shows different ink to use.

Letterpress printing was the normal form of printing text from its invention by [[Johannes Gutenberg]] in the mid-15th century and [[Global spread of the printing press|remained in wide use for books and other uses]] until the second half of the 20th century, when [[offset printing]] was developed. More recently, letterpress printing has seen a revival in an artisanal form.

===Offset===
{{Main|Offset press}}
[[File:The 910 ton printing presses at the Las Vegas Review-Journal were the largest in the world when installed in 2000.webm|thumb|The 910-ton printing presses at the [[Las Vegas Review-Journal]] were the largest in the world when installed in 2000]]
Offset printing is a widely used modern printing process. This technology is best described as when a positive (right-reading) image on a printing plate is inked and transferred (or "offset") from the plate to a rubber blanket. The blanket image becomes a mirror image of the plate image. An offset transfer moves the image to a printing substrate (typically paper), making the image right-reading again. Offset printing uses a lithographic process which is based on the repulsion of oil and water. The offset process employs a flat (planographic) image carrier (plate) which is mounted on a press cylinder. The image to be printed obtains [[ink]] from ink rollers, while the non-printing area attracts an (acidic) film of water, keeping the non-image areas ink-free. Most offset presses use three cylinders: Plate, blanket, impression. Currently, most books and newspapers are printed using offset lithography.

===Gravure===
{{Main|Rotogravure}}
Gravure printing is an [[intaglio printing]] technique, where the image being printed is made up of small depressions in the surface of the printing plate. The cells are filled with ink, and the excess is scraped off the surface with a doctor blade. Then a rubber-covered roller presses paper onto the surface of the plate and into contact with the ink in the cells. The printing cylinders are usually made from copper plated steel, which is subsequently chromed, and may be produced by diamond engraving; etching, or [[laser]] ablation.

Gravure printing is known for its ability to produce high-quality, high-resolution images with accurate color reproduction and using viscosity control equipment during production.
Ink evaporation control affects the change in the color of the printed image.

Gravure printing is used for long, high-quality print runs such as magazines, mail-order catalogues, packaging and printing onto fabric and wallpaper. It is also used for printing postage stamps and decorative plastic laminates, such as kitchen worktops.

===Flexography===
[[Flexography]] is a type of relief printing. The relief plates are typically made from [[photopolymer]]s.
The process is used for flexible packaging, corrugated board, labels, newspapers and more. In this market it competes with gravure printing by holding 80% of the market in US, 50% in Europe but only 20% in Asia.<ref name="IzdebskaThomas2015">{{cite book|author1=Joanna Izdebska|author2=Sabu Thomas|title=Printing on Polymers: Fundamentals and Applications|url=https://books.google.com/books?id=IjROBQAAQBAJ&pg=PP1|date=24 September 2015|publisher=Elsevier Science|isbn=978-0-323-37500-9|page=199}}</ref>

===Other printing techniques===
The other significant printing techniques include:
* [[Dye-sublimation printer]]
* [[Inkjet]], used typically to print a small number of books or packaging, and also to print a variety of materials: from high quality papers simulating offset printing, to floor tiles. Inkjet is also used to apply mailing addresses to direct mail pieces
* [[Laser printing]] (toner printing) mainly used in offices and for transactional printing (bills, bank documents). Laser printing is commonly used by direct mail companies to create variable data letters or coupons.
* [[Pad printing]], popular for its ability to print on complex three-dimensional surfaces
* [[Relief print]], mainly used for [[Mail-order catalog|catalogues]]
* [[Screen printing]] for a variety of applications ranging from T-shirts to floor tiles, and on uneven surfaces
* [[Intaglio (printmaking)|Intaglio]], used mainly for high value documents such as currencies.
* [[Thermal printing]], popular in the 1990s for fax printing. Used today for printing labels such as airline baggage tags and individual price labels in supermarket deli counters.