Computer to film (CTF) is a print workflow involving printing from a
computer
A computer is a machine that can be programmed to Execution (computing), carry out sequences of arithmetic or logical operations (computation) automatically. Modern digital electronic computers can perform generic sets of operations known as C ...
straight to
film
A film also called a movie, motion picture, moving picture, picture, photoplay or (slang) flick is a work of visual art that simulates experiences and otherwise communicates ideas, stories, perceptions, feelings, beauty, or atmosphere ...
through an imagesetter. Designs are typically created in
Adobe Illustrator
Adobe Illustrator is a vector graphics editor and design program developed and marketed by Adobe Inc. Originally designed for the Apple Macintosh, development of Adobe Illustrator began in 1985. Along with Creative Cloud (Adobe's shift to month ...
or
CorelDRAW
CorelDRAW is a vector graphics editor developed and marketed by Corel Corporation. It is also the name of the Corel graphics suite, which includes the bitmap-image editor Corel Photo-Paint as well as other graphics-related programs (see below). T ...
, however they can also be produced in
AutoCAD
AutoCAD is a commercial computer-aided design (CAD) and drafting software application. Developed and marketed by Autodesk, AutoCAD was first released in December 1982 as a desktop app running on microcomputers with internal graphics controllers. ...
,
Inkscape
Inkscape is a free and open-source vector graphics editor used to create vector images, primarily in Scalable Vector Graphics (SVG) format. Other formats can be imported and exported.
Inkscape can render primitive vector shapes (e.g. rectang ...
and many other vector based
CAD
Computer-aided design (CAD) is the use of computers (or ) to aid in the creation, modification, analysis, or optimization of a design. This software is used to increase the productivity of the designer, improve the quality of design, improve co ...
,
design
A design is a plan or specification for the construction of an object or system or for the implementation of an activity or process or the result of that plan or specification in the form of a prototype, product, or process. The verb ''to design'' ...
and
desktop publishing
Desktop publishing (DTP) is the creation of documents using page layout software on a personal ("desktop") computer. It was first used almost exclusively for print publications, but now it also assists in the creation of various forms of online c ...
software packages. An imagesetter is an ultra-high resolution large-format computer output device for CTF.
For multi-coloured printing, the image is broken up into multiple layers representing each of the
spot colors or the
CMYK process colors, this may be split manually by the designer or separated by software in the imagesetter itself. Each color is made into its own piece of film and plate. There can be 12 or more colors used in a single production run; however, 1-6 colors are typical.
From the imagesetter, the film is taken to the plate maker, where the film is laid on top of
photopolymer plate material. A vacuum is then drawn to ensure tight contact between the plate and film, the plate is then exposed with
UV Light
Ultraviolet (UV) is a form of electromagnetic radiation with wavelength from 10 nm (with a corresponding frequency around 30 PHz) to 400 nm (750 THz), shorter than that of visible light, but longer than X-rays. UV radiation i ...
. The plate is then washed in a solvent solution, typically water, where the unexposed areas wash away leaving a
relief
Relief is a sculptural method in which the sculpted pieces are bonded to a solid background of the same material. The term ''relief'' is from the Latin verb ''relevo'', to raise. To create a sculpture in relief is to give the impression that the ...
. It's then dried and given a second and final exposure without the film for durability. The plate can then be fitted onto an
offset
Offset or Off-Set may refer to:
Arts, entertainment, and media
* "Off-Set", a song by T.I. and Young Thug from the '' Furious 7: Original Motion Picture Soundtrack''
* ''Offset'' (EP), a 2018 EP by singer Kim Chung-ha
* ''Offset'' (film), a 200 ...
,
rotary or
flexographic
Flexography (often abbreviated to flexo) 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 a ...
printing press ready to print the product. A printing plate can produce 100,000 impressions or more before showing signs of wear, after which a new plate can be made from the original film.
With advances in the technology of heat stabilization of
polyester
Polyester is a category of polymers that contain the ester functional group in every repeat unit of their main chain. As a specific material, it most commonly refers to a type called polyethylene terephthalate (PET). Polyesters include natural ...
film, new-generation
laser printer
Laser printing is an electrostatic digital printing process. It produces high-quality text and graphics (and moderate-quality photographs) by repeatedly passing a laser beam back and forth over a negatively-charged cylinder called a "drum" to d ...
films provide excellent
image registration
Image registration is the process of transforming different sets of data into one coordinate system. Data may be multiple photographs, data from different sensors, times, depths, or viewpoints. It is used in computer vision, medical imaging, milit ...
and sharpness for multi-colour jobs.
Computer to film is being replaced by the more advanced
computer to plate Computer-to-plate (CTP) is an imaging technology used in modern printing processes. In this technology, an image created in a Desktop Publishing (DTP) application is output directly to a printing plate.
This compares with the older technology, co ...
(CTP) technology.
Printing terminology
Print production
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