Computer to film (CTF) is a print workflow involving printing from a computer straight to film through an imagesetter. Designs are typically created in Adobe Illustrator or CorelDRAW, however they can also be produced in AutoCAD, Inkscape and many other vector based CAD, design and desktop publishing 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. The plate is then washed in a solvent solution, typically water, where the unexposed areas wash away leaving a relief. 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, rotary or flexographic 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 film, new-generation laser printer films provide excellent image registration and sharpness for multi-colour jobs.
Computer to film is being replaced by the more advanced computer to plate (CTP) technology.
In computing, a printer is a peripheral machine which makes a persistent 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.
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 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. Except in the case of monotyping, all printmaking processes have the capacity to produce identical multiples of the same artwork, which is called a print. Each print produced is considered an "original" work of art, and is correctly referred to as an "impression", not a "copy". However, impressions can vary considerably, whether intentionally or not. Master printmakers are technicians who are capable of printing identical "impressions" by hand. Historically, many printed images were created as a preparatory study, such as a drawing. A print that copies another work of art, especially a painting, is known as a "reproductive print".
The CMYK color model is a subtractive color model, based on the CMY color model, used in color printing, and is also used to describe the printing process itself. CMYK refers to the four ink plates used in some color printing: cyan, magenta, yellow, and key (black).
Typesetting is the composition of text by means of arranging physical type in mechanical systems or glyphs in digital systems representing characters. Stored types are retrieved and ordered according to a language's orthography for visual display. Typesetting requires one or more fonts. One significant effect of typesetting was that authorship of works could be spotted more easily, making it difficult for copiers who have not gained permission.
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.
Dots per inch is a measure of spatial printing, video or image scanner dot density, in particular the number of individual dots that can be placed in a line within the span of 1 inch (2.54 cm). Similarly, dots per centimetre refers to the number of individual dots that can be placed within a line of 1 centimetre (0.394 in).
In color reproduction, including computer graphics and photography, the gamut, or color gamut, is a certain complete subset of colors. The most common usage refers to the subset of colors which can be accurately represented in a given circumstance, such as within a given color space or by a certain output device.
Digital printing is a method of printing from a digital-based image directly to a variety of media. It usually refers to professional printing where small-run jobs from desktop publishing and other digital sources are printed using large-format and/or high-volume laser or inkjet printers.
Prepress is the term used in the printing and publishing industries for the processes and procedures that occur between the creation of a print layout and the final printing. The prepress procedure includes the manufacture of a printing plate, image carrier or form, ready for mounting on a printing press, as well as the adjustment of images and texts or the creation of a high-quality print file. In today's prepress shop, the form of delivery from the customer is usually electronic, either a PDF or application files created from programs such as Scribus, Adobe InDesign, Adobe Illustrator, or QuarkXPress.
Within the commercial printing industry, the job of stripping involves arranging and joining film negatives as part of the process of preparing printing plates. In the UK, the same operation is termed "planning" and film positives are used, rather than the negatives in the USA. Because the industry has largely moved to digital processes, the job of stripping, or planning has become rare or even obsolete.
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. Using a printing press, the process allows many copies to be produced by repeated direct impression of an inked, raised surface against sheets 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.
Color printing or colour printing is the reproduction of an image or text in color. Any natural scene or color photograph can be optically and physiologically dissected into three primary colors, red, green and blue, roughly equal amounts of which give rise to the perception of white, and different proportions of which give rise to the visual sensations of all other colors. The additive combination of any two primary colors in roughly equal proportion gives rise to the perception of a secondary color. For example, red and green yields yellow, red and blue yields magenta, and green and blue yield cyan. Only yellow is counter-intuitive. Yellow, cyan and magenta are merely the "basic" secondary colors: unequal mixtures of the primaries give rise to perception of many other colors all of which may be considered "tertiary."
In printing, trap expresses the degree to which ink already printed on a substrate accepts another layer printed on top of it compared to how well the substrate accepts that ink.
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.
In printing, Preflight is the process of confirming that the digital files required for the printing process are all present, valid, correctly formatted, and of the desired type. The basic idea is to prepare the files to make them feasible for the correct process such as offset printing and eliminate costly errors and facilitate a smooth production. It is a standard prepress procedure in the printing industry. The term originates from the preflight checklists used by pilots. The term was first used in a presentation at the Color Connections conference in 1990 by consultant Chuck Weger, and Professor Ron Bertolina was a pioneer for solutions to preflighting in the 1990s.
A contract proof usually serves as an agreement between customer and printer and as a color reference guide for adjusting the press before the final press run. Most contract proofs are a prepress proof.
A photolith film is a transparent film, made with some sort of transparent plastic. Nowadays, with the use of laser printers and computers, the photolith film can be based on polyester, vegetable paper or laser film paper. It is mainly used in all photolithography processes.
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