Glossary of Digital Terms

Glossary of Commonly Used Digital Print Terms

Aqueous Inks: -- Inks that use water as a carrier. Typically, aqueous inks use either dyes or pigments as colorants.

Banding: -- A pattern of horizontal or vertical lines that occurs in solid colors, continuous-tone tints, or gradations instead of a smooth color or color transition. Banding can appear on computer monitors when viewing images with less than 24-bit information, on printers due to a problem with the shape of the curve or due to improperly built file elements.

Back to Back Printing -- Unlike Double Sided Printing where an image is printed on both sides of the same media, Back to Back printing refers to Printing both images on the same side, then folding over the media resulting in a double sided graphic. These graphics are usually perimeter stitched sometimes with a block –out layer in-between. This printing is used when the media does not support printing on both sides, due to coating or lack there of.

Bitmap -- Graphics constructed of individual pixels arranged in specific patterns. Bitmap-image formats include, by filename extension…

Al = Adobe Illustrator Encapsulated PostScript
BMP = Windows Bitmap
EPS = Encapsulated PostScript
GIF = Graphics Exchange Format
JPEG or JPG = Joint Photographic Experts Group
PCD = Kodak Photo CD
PCX = ZSoft Paintbrush Exchange
PDF = Adobe Acrobat Portable Document Format
PICT, PCT = QuickDraw Picture Format
RTL = Raster Transfer Language

PNG = Portable Network Graphics, created to replace GIF’s
SCT = Scitex
TGA = Targa
TIF or TIFF = Tagged Image File Format

Bleed -- Printing an image past where the final print will be trimmed, which allows color to extend all the Way to the edges of the final print.

Bounding Box -- Bounding Box’s in PostScript page-description language are rectangles defining the area of an image. The area of an on-screen image at its maximum X and Y axes measurements. Altering the bounding box by moving its control points can change the shape or size of an image. Bounding boxes allow scaling of graphics in page-layout soft-ware.

C1S and C2S -- Abbreviations for Coated One Side and Coated Two Sides.

Camera Raw: -- An image file format for digital cameras containing unprocessed data. Also called RAW (not an acronym) or CCD-RAW, the format is proprietary and differs between camera makers (and sometimes between models from one manufacturer). RAW image files must be processed and converted to an RGB format before they can be manipulated by a bitmap graphics editor, printed or displayed by a Web browser

Cast Films -- Cast film stays in a more relaxed state, resulting in a durable, flexible, conformable and dimensionally stable film that retains color well. These films are ideal for complex surfaces such as vehicles and where a smooth finished look is expected.

Calendared Films -- Calendared Films are often called intermediate or short-term films. These films are well suited for flat and simple curved applications on a variety of substrates.

CMYK (Cyan, Magenta, Yellow, and Black) -- The four process colors, which are used by output devices such as inkjet, electrostatic and thermal transfer printers. Black is called “K” because in process printing it is the key plate or Keyline color. Mixed to provide a color image; typically used in printing applications.

Color Calibration -- Software and/or hardware that coordinates the color match between two or more digital devices.

Color Curve -- Visual control used in photo-illustration and other graphics software to display color measurements and make tonal chances to an image.

Colorimeter -- An optical device that measures absorbance of light by filtering reflected light into regions of red, green and blue. While dedicated colorimeters do exist, most instruments actually spectro-photometers that compute colorimetric values based on spectral reflectance or transmittance curves.

Color Management -- Refers to coordination of color among input, display and output devices. In output, color management is often handled on a device-by-device basis by imaging production software (see RIP). In display and other tasks, coordination often comes via device-specific software such as Apple ColorSync or Adobe Photo-shop.

Color Modes -- Models of tones based upon different coordinate values, such as; hue, luminance, and saturation (HLS); hue, saturation and brightness (HSB); hue, saturation and value (HSV); red, green and blue (RGB); and cyan, magenta, yellow and black (CMYK).

Color Space -- Definition of color by theoretical three-dimensional graphing. Colors are determined by plotting points using particular values (such as red, green and blue). Used in most cases to represent the range of variations of particular color combinations, such as RGB or CMYK.

Compression -- In color management, gamut compression refers to the ability of software to reduce the range of colors in an image to that which can be reproduced on an output device. In image processing, file compression refers to reducing the size of a file through and alternate encoding process.

Continuous Tone -- Method of printing in which equally sized color dots are place in a variable-spaced pattern, creating the effect of more natural color transitions.

Contour Cut -- with print-and-cut digital-printing device, posses the ability to cut around the outline of an image, both on the outer boarder and along any internal borders.

Crop Marks -- Lines near the edges of an image indicating portions to be reproduced. Also called cut marks and tic marks.

Crossover – Type or art that continues from one page across the gutter to the opposite page. Also called bridge, gutter bleed and gutter jump.

Delta-E (DE) -- Measurement unit in a uniform color space of the perceivable differences in color viewable by the human eye. The first noticeable change is 2 DE. Delta-E measurement is used, for example, by customers specifying and accepting color, and in manufacturer guarantees of colorfastness.

Double Sided -- Not be confused with Back to Back printing, Double sided printing is achieved by printing the image on both sides of the same media. A large number of Medias are offered with coating on both sides in order to achieve this goal.

DPI (Dots Per Inch) -- Unit of measure use to describe the printing resolution of and output device, or the printed resolution of an output device, or the printed resolution of images, based on the number of separate ink droplets representing either horizontally or vertically in one inch. Also correlates to pixels per inch and samples per inch. DPI is a significant influence on the size of an image file; a high DPI indicates higher resolution.

Dye Sublimation -- Color printing technology that creates a photo-graphic-quality image by delivering gaseous dyes to a receiver material using a thermal transfer system usually involving transfer paper and a heat press.

Eco-Solvent Inks -- A type of solvent ink that employs a less-toxic carrier, generally dipropylene glycol monomethyl ether. Printers using eco-solvent inks emit fewer harmful VOCs (volatile organic com-pounds) than standard solvent inks.

Embedded Files – Pertains to Adobe Illustrator files. Embedded artwork actually becomes part of the Illustrator document. This can dramatically increase the size of the file and slow down processing speed. It does ensure that an image will be included when you send the file to be output.

EPS (Encapsulated PostScript) – An Adobe graphic file format; allows different information, such as colors and fill patterns, to be carried between software programs. Flies can include bitmap and vector information, including low-resolution files for thumbnail pre-views. Versions of this include variations from Adobe Illustrator (with .AI filename extensions). EPS files hold both low-resolution view files and high-resolution postscript image descriptions.

Flood White – Printing application in which a solid field of white ink that is laid down to be over-printed with and image, as when printing onto a non-white surface.

Flattened Image – In a flattened image, all visible layers are merged into the background, greatly reducing file size. Flattening an image discards all hidden layers and fills the remaining transparent areas with white. In most cases, you won't want to flatten a file until you have finished editing individual layers. Keep in mind, once a file is flattened, there’s very little you can edit.

Flat size – Size of product after printing and trimming, but before folding, as compared to finished size.

Four Color Process -- Technique of printing that uses black, magenta, cyan and yellow to simulate full-color images. Also called color process printing, full color printing and process printing.

FPO –For Position Only,  refers to inexpensive or low resolution copies of photos or art used in layouts to indicate placement and scaling, but not intended for reproduction.

FTP (File Transfer Protocol) – Technically, FTP is a language used to moved files; however, the term commonly refers to the process of sending a file via FTP or to an FTP site. FTP is used as opposed to HTTP, which is the language used to write web pages, The 'ftp' or 'http' that precedes a web address tells a web browser which language it should use when processing the request.

GCR (Gray Component Replacement) – Color separation process in which black ink is used to replace cyan, magenta, and yellow (CMY) in mid-tome and highlight areas where the three inks overlap, in order to reduce ink consumption and drying time. (Similar to UCR.)

Grain direction – Predominant direction in which fibers in paper become aligned during manufacturing. Also called machine direction.

Gradation – Steps of transition between two colors between black and white. This is performed by progressively mixing percentages of a dominant and secondary color in alternation. (Sometimes referred to as “gradient.”)

Gutter -- In the book arena, the inside margins toward the back or the binding edges.

Grommet – Metal rings which can be inserted along the edges .of a banner/billboard to be used for installation purpose, Hem: A process whereby vinyl is welded (not sewn), using intense heat to seam tow or ore pieces of vinyl together.

Higher Resolution -- Means more detail. Higher DPI means higher resolution1. Resolution is not “size”, but it’s often

Confused with it because higher resolution images are often bigger, but that doesn’t necessarily have to be the case.

Indicia – Postal permit information printed on objects to be mailed and accepted by U.S. Postal Service in place of stamps.

Image Resolution -- is the detail an image holds. The term applies to raster digital images, film images, and other types of images. Higher resolution means more image detail.

Interpolation – Software technique used to increase the size of an image file by creating more pixels, using mathematical averaging to increase tonal value and apparent resolution.

JPEG/JPG (Joint Photographic Experts Group) – Graphic file format designed for use with photographs and other color bitmaps. The JPEG format uses a mathematical compression technique to reduce file size by removing a user-selectable percentage of the images data information. Usually used for compressing full-color or grayscale images. Primarily used for screen and web display rather than printing due to its low resolution.

L*a*b – Color space calculated with values of lightness (L) and attributes of red-green (a) and yellow-blue (b). Most commonly associated with CIE for a non-device-dependent coordination of color. The two dimensional reference defines colors and color spaces based upon physiological measurements of human color vision.

Layers – Pertains to Adobe Photoshop and Illustrator files. Layers are best described as sheets of acetate stacked one on top of the other. Where there is no image on a layer, you can see through to the layers below. All layers in a file have the same resolution and have the same color characteristics.

Light Magenta/Light Cyan/Light Yellow/Light Black (Lm/Lc/Ly/Lb) – Muted or diluted forms of two subtractive primaries which, when used with CMYK inks, enable finer highlight detail, expands color gamut and provides a less noticeable dot structure for more natural-looking continuous tone prints.

Linearization – The process of calibrating the time values on a scanner or printer to create evenly distributed tones capable of rendering detail throughout an image.

Low Res – files which have a "low resolution" DPI or "dots per square inch” count

Midtones – In a photograph or illustration, tones created by dots between 30 percent and 70 percent of coverage, as compared to highlights and shadows.

Opacity – Measurement of the resistance to light passing through a substrate, on a scale of 0-100%, indicting the propensity for show-through of underlying type or images. This is computed by measuring the density of the substrate over a black background and over a white background.

Overprint – Standard in process color, the placement of one color over another to create varying tones and shades. Also used with individual spot colors to create other colors

Overprint White – Printing application in which white ink is used as a background for reverse-printed transparent stocks, such as back-lit images. White in this application should be somewhat translucent.

Pagination -- The assignment of page numbers, either manually or electronically, in a document.

PANTONE® Matching System – Numbering system for identifying 3,000+ colors created through combinations of 14 primary color inks. Pantone produces numerous color-matching systems for standard print and computer applications.

PDF (Portable Document System) – Electronic document format from Adobe Systems Inc. that allows the distribution of files across platforms that can display a document as originally designed and formatted – and, when fully developed, also allow printing – without requiring the original software application or fonts on the viewing computer.

PPI -- Pixels per inch. Most commonly used to describe the pixel density of a screen (computer monitor, Smartphone, etc…) but can also refer to the pixel density of a digital image.

Pole Pockets – Similar to pockets but typically refer to the type of pocket used for hanging banners. They are usually 3" in depth, and are used by outdoor companies to literally insert a pole through, which is then secured to the structure using hooks and or ratchet straps.

PostScript – Graphics language that creates vector-based images that, by computer code, allows for proportional scaling. It makes most scalable type and artwork possible for Windows- and Macintosh-based graphics software.

PMS – Commonly used referencing term to PANTONE Matching System.

Primary Colors – Color that cannot be created by missing other color in the gamut of a given color space, but can be mixed to create other color combinations within the space, red, green, and blue (RGB) are additive primaries of emitted light, while cyan, magenta and yellow (CMY) are subtractive primaries of reflected light. Black (K) is added to CMY to produce denser, truer black images.

Process Color – Cyan, magenta, yellow and black (CMYK), combined in a matching system to recreate thousands of colors in offset and direct digital printing.

Plug-Ins – Small, limited-purpose programs that work with and add capabilities to larger graphics applications.

Print Resolution -- This term can describe either how many pixels a screen can display or how fine a printer can print. 300dpi is standard, sometimes 150dpi is acceptable but never lower, you may go higher for some situations.

Raster Image – An image comprised of a collection of pixels arranged in a rectangular array. The image is displayed as a series of lines of dots, as opposed to 'vector image",

Rasterization – Translating data to a specific bitmap pattern for use by a digital printing device.

Resize – Change of reproduction size. Files can generally be resized so prints can be made smaller or larger. Significant up-sizing often results in jaggies, but an adjustment of up to 20% is acceptable.

Resolution – The number of pixels or samples per inch in a device is capable of recognizing or producing, measured in horizontal columns (width) by vertical rows (height). Megapixels can be calculated by multiplying pixel-columns with pixel-rows. Resolution is a measure of the detail in an image; the higher the resolution the higher the amount of detail and the bigger the file size.

Reverse / Knockout Type -- graphic or illustration reproduced by printing ink around its outline, thus allowing the underlying color or paper to show through and form the image. Also called knockout and liftout. The image “reverses out” of the ink color.

RGB (Red, Green and Blue) – The three additive colors used by monitors and scanners for transferring and representing color data. The rule of thumb in imaging is that input and display are in RGB, while output is done in CMYK. RGB is typically used in video display applications.

RIP (Raster Image Processor) – Software and/or hardware used to convert data to bitmap information for processing on a PostScript printer or other digital device. This computer-calculation-intensive process determines 360,000 combinations and color placements to print every square inch of a 300 DPI image using CMYK process colors. Each process color is a color separation. This action is referred to as RIPing or Rasterization.

Saturation – The intensity of a specific hue, based on the color’s purity, measured from 0-100% in the HSV color model. Highly saturated hues have vivid color, while less saturated hues appear grayish.

Solvent Inks – Inks that use a solvent, generally cyclohexanone , as a carrier and are commonly used for printing onto vinyl, as they offer good outdoor durability. Printers using solvent-based inks emit VOCs and should be ventilated.

Spot Colors – Color times used independently in a printed piece for a specific need (i.e., Coca-Cola’s shade of red), or in overlapping combinations (including those with process colors).

Spot White – An application in which white ink is used as an independent color (usually for printing text or logos on a non-white surface).

Spread – 1) Two pages that face each other and are designed as one visual or production unit. 2) Layout of several photos, especially on facing pages.

UCR (Under Color Removal) – Color separation process in which black ink is used to replace cyan, magenta and yellow (CMY) in shadow areas where the three inks overlap, since black (K) in the combination of CMY. (Similar to GCR.)

UV-curing – Printing process in which a lamp emitting ultra violet (UV) rays is used to transform monomer-based liquid inks (deposited onto a substrate) into polymer-based solid inks. Commonly used curing technology in many digital flatbed printers.

Vector Image – A computer image that used geometrical primitives (such as points, line, polygons and Bezier curves) to produce mathematical descriptions of paths for the graphic.

Web/Digital -- DPI doesn’t equate to digital it’s a print measurement. It was commonly believed for a long that 72dpi was ideal for the web. When talking digital, we’re concerned with the actual image/art resolution. How that image prints is another matter.