This article needs additional citations for verification . (March 2011) (Learn how and when to remove this template message) |
Stochastic screening or FM screening is a halftone process based on pseudo-random distribution of halftone dots, using frequency modulation (FM) to change the density of dots according to the gray level desired. Traditional amplitude modulation halftone screening is based on a geometric and fixed spacing of dots, which vary in size depending on the tone color represented (for example, from 10 to 200 micrometres). The stochastic screening or FM screening instead uses a fixed size of dots (for example, about 25 micrometres) and a distribution density that varies depending on the color’s tone.
The technique of stochastic screening, which has existed since the seventies,[ citation needed ] has had a revival in recent times thanks to increased use of computer-to-plate (CTP) techniques. In previous techniques, computer to film, during the exposure there could be a drastic variation in the quality of the plate. It was a very delicate and difficult procedure that was not much used. Today, with CTP during the creation of the plate you just need to check a few parameters on the density and tonal correction curve. When you make a plate with stochastic screening you must use a tone correction curve, this curve allows one to align the tone reproduction of an FM screen to that of an industry standard. Given the same final presswork tone value, an FM screen utilizes more halftone dots than an AM/XM screen. The result is that more light is filtered by the ink and less light simply reflects off the surface of the substrate. The result is that FM screens exhibit a greater color gamut than conventional AM/XM halftone screen frequencies. The creation of a plate with stochastic screening is done the same way as is done with an AM/XM screen. A tone reproduction compensation curve is typically applied to align the stochastic screening to conventional AM/FM tone reproductions targets (e.g. ISO 12647-2).
The small dots used in FM screening require special care and cleanliness, especially when plates are made from films. [2]
Printmaking is the process of creating artworks by printing, normally on paper. Printmaking normally covers only the process of creating prints that have an element of originality, rather than just being a photographic reproduction of a painting. Except in the case of monotyping, the process is capable of producing multiples of the same piece, 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". Often impressions vary considerably, whether intentionally or not. The images on most prints are created for that purpose, perhaps with 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).
A raster image processor (RIP) is a component used in a printing system which produces a raster image also known as a bitmap. Such a bitmap is used by a later stage of the printing system to produce the printed output. The input may be a page description in a high-level page description language such as PostScript, PDF, or XPS. The input can be or include bitmaps of higher or lower resolution than the output device, which the RIP resizes using an image scaling algorithm.
Halftone is the reprographic technique that simulates continuous-tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect. "Halftone" can also be used to refer specifically to the image that is produced by this process.
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, the more newly introduced dots per centimeter refers to the number of individual dots that can be placed within a line of 1 centimeter (≈ 0.393 in).
Stippling is the creation of a pattern simulating varying degrees of solidity or shading by using small dots. Such a pattern may occur in nature and these effects are frequently emulated by artists.
Digital printing means to methods 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. Digital printing has a higher cost per page than more traditional offset printing methods, but this price is usually offset by avoiding the cost of all the technical steps required to make printing plates. It also allows for on-demand printing, short turnaround time, and even a modification of the image used for each impression. The savings in labor and the ever-increasing capability of digital presses means that digital printing is reaching the point where it can match or supersede offset printing technology's ability to produce larger print runs of several thousand sheets at a low price.
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 such programs as Scribus, Adobe InDesign, Adobe Illustrator, or QuarkXPress.
Screentone is a technique for applying textures and shades to drawings, used as an alternative to hatching. In the conventional process, patterns are transferred to paper from preprinted sheets, but the technique is also simulated in computer graphics, notably in Flipnote Studio and Macpaint. It is also known by the common brand names Zip-A-Tone, Chart-Pak (1949), and Letratone.
Offset printing is a commonly used printing technique in which the inked image is transferred from a plate to a rubber blanket, 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.
Frederic Eugene Ives was a U.S. inventor, born at Litchfield, Connecticut. In 1874–78 he had charge of the photographic laboratory at Cornell University. He moved to Philadelphia, Pennsylvania, where in 1885 he was one of the founding members of the Photographic Society of Philadelphia. He was awarded the Franklin Institute's Elliott Cresson Medal in 1893, the Edward Longstreth Medal in 1903, and the John Scott Medal in 1887, 1890, 1904 and 1906. His son Herbert E. Ives was a pioneer of television and telephotography, including color facsimile.
Photogravure is an intaglio printmaking or photo-mechanical process whereby a copper plate is grained and then coated with a light-sensitive gelatin tissue which had been exposed to a film positive, and then etched, resulting in a high quality intaglio plate that can reproduce detailed continuous tones of a photograph.
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."
Dot gain, or tonal value increase, is a phenomenon in offset lithography and some other forms of printing which causes printed material to look darker than intended. It is caused by halftone dots growing in area between the original printing film and the final printed result. In practice, this means that an image that has not been adjusted to account for dot gain will appear too dark when it is printed. Dot gain calculations are often an important part of a CMYK color model.
Dither is an intentionally applied form of noise used to randomize quantization error, preventing large-scale patterns such as color banding in images. Dither is routinely used in processing of both digital audio and video data, and is often one of the last stages of mastering audio to a CD.
CcMmYK, sometimes referred to as CMYKLcLm or CMYKcm, is a six-color printing process used in some inkjet printers optimized for photo printing. It complements the more common four color CMYK process, which stands for Cyan, Magenta, Yellow and Key (black), by adding light cyan and light magenta. Individually, light cyan is often abbreviated to Lc or c, and light magenta is represented as Lm or m.
In the theory of photography, tone reproduction is the mapping of scene luminance and color to print reflectance or display luminance, with the aim of subjectively "properly" reproducing brightness and "brightness differences".
The Approval proofer, also known as the Approval Digital Imaging System or Kodak Approval System, was designed for use in Prepress proofing, especially for the highest quality contract proofs.
A process camera is a specialised form of camera used for the reproduction of graphic material. Before the advent of color scanners, color process work was undertaken by the process camera, by a skilled operator. This was achieved by using various filters to produce a set of 4 film separations, cyan, magenta, yellow and Black (CMYK), this in turn was usually color corrected by another tradesman called a color retoucher. After the introduction of color scanners in the 1970s, the process camera was gradually only used for monochrome line-work or less often monochrome tone-work. The original artwork was photographed and the negatives produced were eventually used to production of printing plates.
Gradation in art is a visual technique of gradually transitioning from one colour hue to another, or from one shade to another, or one texture to another. Space, distance, atmosphere, volume, and curved or rounded forms are some of the visual effects created with gradation.
We have always printed black solid text using 100pc black ink but ...we intend to reduce all text to a 90pc screen. This does not affect quality in any way but it does save on ink. Archant is the only newspaper company in this country capable of undertaking this because of its FM screen technology. Traditional newspaper AM screen technology would have resulted in fine text becoming grainy....Photographs will be unaffected and it will also have the added benefit of less black ink rub off. The process involves punching tiny holes, which are invisible without a magnifying glass, into the font.