Glossary of terms

Technical terms simply explained

ICC, International Color Consortium Comité International de la Couleur international consortium of companies and institutions of the graphics and computer industry, established in 1993 at the initiative of Fogra. The goal, which has meanwhile been achieved, was the creation of a cross-platform standard for media and device-independent processing of color data (“color management”) in the form of the device characterization format “ICC Profile Format”, which allows the support of compliant software applications at operating system level.

ICC Profile Format format de profil ICC color table format following the tag structure of TIFF, the version 4 of which was published as ISO 15076-1:2010 (still available for download free of charge at color.org). Besides the actual profile file format, the architecture of a color management system, rendering intents and the embedding of the profiles are also described.

ICC profile profil ICC standardized data file which describes the color space or the color rendering properties of input, reproduction or output devices; see Tables I-2 “ICC profiles classification” on page 56

ICC-compliant conforme ICC property of software, utilities and drivers which can read, create or in a suitable manner apply ICC profiles. Regardless of this, these applications differ not least in terms of the consistency with which the ICC regulations are fulfilled, so that color management is not implemented largely correctly by all applications. This means therefore that conformity is also characterized by reliable operability and intelligent usability.

illuminanceirradiance éclairement intensity with which a surface is (uniformly) illuminated; SI units are lx [lux] and lm/m² [lumen per square meter], that is, the quotient of luminous flux and illuminated surface; other units are “international lux” (1 ilx = 1.019 lx) and phot (1 ph = 10000 lx).

illuminant illuminant defined spectral radiation distribution (spectral characteristic) of a light source, i.e. their shares in the blue, green and red areas of the visible spectrum, with respect to the effect of optical brighteners but also to their shares in the area close to UV; important standard illuminants: A (lightbulb), D50 (neutral daylight, standard in the printing and media industries), D65 (medium daylight), TL84 (store light/three-band lamp).

image data base base de données d’images archive often implemented as a content management system in which pixel and vector graphics files are saved with head words and administrative data (metadata) and if possible also embedded ICC profiles; loss-free medium-neutral formats are practical (e.g. TIFF RGB, EPS, PDF).

image editing traitement d’image all changes carried out digitally to the image content; global color values: color cast removal (white alignment), use of device profiles, color tune correction, tone value ranges (highlights, medium tones, shadow tones); local color values: color changes; means of working: abstract (RGB, CMYK, CIELAB values) and intuitive (lightness/chromaticness/hue levels).

image quality qualité de l’image criteria for image reproduction; subjective: motif, aesthetics; objective: color rendering, color appearance (CIECAM02), contrast, detail sharpness, noise.

in-gamut color couleur affichable see gamut mapping

in-line measurement mesurage en ligne process or machineintegrated measurement, often as part of a closed loop control system. Example: QualiTronic ColorControl automatic color density control in KBA sheet-fed offset presses with a colorimetric camera as integrated measuring instrument.

incidence angle angle d’incidence irradiation angle which must enclose 45° with the viewing/measuring angle during color matching and color measuring (freedom from gloss).

INCQCInternational Newspaper Color Quality Club club of the research association of the WAN-IFRA newspaper industry, which grants club membership of newspaper printing houses for a period of 2 years on account of the color rendering quality of their printed  products and the color management expertise of its personnel.

indexed colors couleurs indexées see color indexing

indicatrix indicatrice model of the distribution of the reflected/ remitted light in the room. In the center of the indicatrix, under the gloss angle, is the strongly directional radiation share, and around it the weaker diffuse share.

inert gas séchage sous atmosphère inerte creation of a nitrogen protective atmosphere in the radiation curing of ESH printing inks and in long-grain UV offset printing, to rule out the network-inhibiting influence of atmospheric oxygen. In UV printing, heat-sensitive films are printable and higher printing speeds possible through the simultaneously reduced heat input. This was first realized in 2002 in a KBA Rapida 105 installed by the Belgian plastic printer Crea.

infield cache perforé pinhole that takes place in a color comparison. In the color matching of samples, neutral gray stencils with a hole are often used to eliminate the disturbing influences of color stimuli outside the 2° field of view with larger samples. Anyone who has to deal with color should have such pinholes.

ink, paintcolor encre, peinture liquid dyeing substances with a low to high-viscosity consistency, i.e. printing inks, ink-jet inks, wall paints and artist’s colors.

ink agitator agitateur d’encre device for installation in the ink ducts of printing presses, on order to 1. distribute the printing ink evenly over the entire ink duct width by means of an agitator cone and to “apply” it to the fountain roller – especially to be recommended for UV inks, 2. keep the viscosity of thixotropic inks low; an ink agitator that can be set up individually in conjunction with ink mixing software serves to mix the required quantity of special ink in a container.

ink can/container boîtes et fûts métalliques container in which printing ink is sold; label marking scale, pigments, mass, hazard classification, emissions, preset viscosity, temperature window (with waterless offset inks); the most common container types in: 2.5 kg vacuum can and 2 kg cartridge in sheet and heatset offset printing, 200 kg barrel in coldset, also hobbocks in flexo printing.

ink consistency consistance Generic term for the flow properties of a printing ink.

ink consumption consommation d’encre 1) the quantity of printing ink (in g.) required for a print job; calculation through mass difference (100 printed – 100 unprinted sheets in g) × job run / 100; 2) in newspaper printing, the surfacespecific printing ink (in kg/m2) required to achieve a certain relative color density.

ink coverage couverture d’encre coverage of ink on the substrate in overprinting, e.g. in four-color printing a maximum of 400% – see total ink coverage.

ink drying séchage des encres principles of film formation and adhesion promotion in printing inks on substrates: penetration, evaporation (solvents, water), polymerization/condensation (cationic/anionic UV, IR and electron radiation hardening), oxygen bridge formation (oxidation), cooling (phase transition), precipitation (moisture set), sintering/melting (ceramic inks, toner).

ink film thicknessépaisseur du film d’encre film thickness in solid ink application, measurable as solid tone ink density. In order to achieve the required ink thickness of the process colors as well as their required chromaticity coordinates, minimum ink film thicknesses must be printed: CMY 0.7 to 1.1 μm, K 0.9 to 1.3 μm.

ink film/layer film d’encre initially damp printing ink layer on the substrate, where it forms a dry film (“film formation”).

ink flow écoulement de l’encre primarily directional flow of printing ink from the ink duct through the rollers, the print forme and the blanket to the substrate. Breaking it back down leads to a secondary flow in the opposite direction, which can lead to ghosting and can also transport paper fibers etc. into the ink duct. Glazing rollers are used to combat ghosting and uneven distribution of the ink over the front or rear edge of the printed image (front/rear-heavy).

ink formulation and mixing formulation et mélange des encres et peintures creation of printing inks and paints according to color references.

ink leftover use utilisation des encres résiduelles cost-effective inclusion of ink residues in the development of recipes by ink mixture software. Formulation and mixing solutions such as X-Rite Ink Formulation or Connex Alwin II and Winmix are able to incorporate colorimetric measured ink leftovers.

ink metering dosage de l’encre task of the inking units in the printing press. The metering of printing ink can be effected from the central control console in the total ink quantity (by means of fountain or screen roller) and the individual ink keys (by means of ink slides) or is a component in a color control device, e.g. KBA QualiTronic ColorControl. Pre-metering (CIP3 ink key presetting, printing ink profile) on the basis of the print forme data is normal when ink flows at the beginning of a new print job.

ink mixing system station de mélange/dosage system for mixing special inks or blended printing ink supplies, incl. ink residues. An ink mixing system for sheet-fed offset inks consists of a basic ink supply (8 to 12 basic colors), precision scales, a  spectrophotometer, reception software and possibly a mixing and metering system (similar to that in DIY stores). In flexo printing, when pigment concentrate systems are in use, scale as well as special inks are calculated on site and the required quantity is mixed; solvents, blends, white inks and paints are kept in stock for this; the mixing and metering system is suitably dimensioned and is fed from tanks through a system of  pipelines.

ink receptivity accueil/amour de l’encre printability property of a substrate surface, consisting in the ability to absorb printing ink evenly and in sufficient quantity during the printing process from the printing forme, in offset printing from the surface of the blanket, without signs of rejection; metrological characterization by oil absorbency  according to Cobb-Unger.

ink saturation intensité de la couleur color saturation in print, dependent on the surface ink supply and the coverage of the printing ink.

ink scale/set gamme d’encres, série d’encre set of printing inks matching each other in terms of color, e.g. process color, intensive and hifi color scales.

ink stringingstring break-off length détermination du tirant non-standardized rocedure for empirically testing the viscosity of a pasty printing ink on the basis of thread formation or break-off length, which allows conclusions concerning the viscosity and tackiness, that is, the “shorter”, the tackier and the more viscous. Methods: 1. A spatula is inserted at an angle into the printing ink (in the ink container) and then lifted out; 2. thread formation between two fingers. Uncontrolled thread formation in the roller nip leads to mist formation and splashing.

ink supply/feed systems système d’alimentation en encre easy-to-handle or automated solutions for filling the ink duct with little ink waste: cartridges including squeezing devices as well as pumps that transport the ink from large containers using pipes.

ink trapping accrochage/prise de l’encre adhesion of two printing ink layers in wet-in-wet offset printing; measure for the mottling propensity (cloudiness) as well as for the ink splitting of the transferred printing ink between the blanket and the preceding printed layer of ink. Quantification procedure by which the solid densities of the individual inks and of the combined print with the filter of the second-printed ink are measured: ink trapping according to Preucil (DIN 16527, inaccurate); ink trapping according to Ritz (“bead factor”, because poor ink trapping becomes apparent in a beaded printout); ink trapping according to Brunner (most accurate): The higher the percentage, the better the ink trapping; if ink trapping is too low, possibility of change in the color sequence or use of wide-format ink absorbency strips in the trim.

inking encrage setting of the global and zonal ink feed (amenée d’encre) and its continuous visual or technical control as well as its correction during production printing.

inking unit dispositif d’encrage, groupe d’encrage module in printing presses with the purpose of ink transfer; in offset printing a distinction is made between the conventional
(“long”) inking unit and the short inking unit which KBA developed, among other things for waterless newspaper printing (Cortina).

inking-up mise à la teinte in the setup of a print job, the fastest possible and most waste-saving setup of normal inking or (in wet offset printing) the optimum balance between ink and dampening solution.

inking, ink application encrage, application de l’encre the inking up of the print forme with the ink forme rollers.

inkjet inks encres pour impression jet d’encre dispersions of dyes or pigments based on solvents or water containing hardly any binding agents; inkjet inks dry through solvent evaporation or UV radiation-curing.

input device dispositif d’entrée device which records images in an RGB color space (digital camera, scanner, video camera, TV camera).

input targeting calibrage d’entrée creation of so-called characterization data of input devices, in the course of which these photograph/scan a test chart (ISO 12641: transmitted version IT8.7/1, reflected version IT8.7/2) and compare the RGB data of the color fields in the image file (actual data) with the target data of the test chart using suitable software. These data can be used to create ICC input profiles which can later be embedded in all image data created by these devices. The software basICColor input contains not only ISO test charts but also proprietary targets (HutchColor,  ColorChecker, ColorChecker DC/SG, basICColor dcam target+) and can, among other things, create its own targets, edit special colors and retain the camera gray balance values.

interchange color spaceICS espace colorimétrique d’échange color space for saving and transferring image data; usually media-neutral RGB, more rarely CIELAB or outputoriented CMYK.

interference pigments pigments interférentiels colorless or colored pigments which develop their chromatic effect through total reflection in thin transparent layers; the best known are lustrous pigments (e.g. Merck Iriodin), silicon dioxide (color flop) and BASF Paliocolor (liquid crystals).

interinstrumental agreement accord interinstrument correspondence of the measured values within one series of measuring devices (manufacturing tolerances).

interpolation interpolation process for the creation of image contents between pixels (apparent increase in output resolution, without impairing output speed) or within individual pixels (increase in color depth) compared with the original dataset.

intuitive intuitif form of natural processing of color stimuli; human beings do not perceive color in an abstract way as a wavelength, but distinguish color shades “by inspiration”, by hue, saturation/chromaticness and brightness; intuitively understandable color space models (CIELCH) and color ordering systems (Munsell scale) are therefore also extremely userfriendly for graphic designers.

inversion inversion conversion of the color data of a positive image into a negative image.

IPS, In-Plane Switching liquid crystal deflection in active matrix displays in which the electrodes are side by side in one plane parallel with the display surface and in which the molecules rotate in the screen plane when voltage is applied. IPS improves the viewing angle dependency of the contrast and achieves high color trueness and stability. Variants: S-IPS (Super-IPS), AS-IPS (Advanced Super IPS), H-IPS (Horizontal IPS), H-IPS A-TW (Advanced True White H-IPS). H-IPS is the only IPS panel that does not have a violet shimmer when viewed from the side. For this reason, NEC chose and further improved this technology for its wide-gamut monitors.

IR, infrared, heat infrarouges, chaleur band of invisible wavelengths which are used in the printing industry for the heat drying of printing inks and varnishes, as well as in the thermoimaging of printing plates.

ISO, International Organization for Standardization Organisation internationale de normalisation committee that commissions groups of experts to develop worldwide valid standards; for the graphics industry Technical Committee 130

IT8 targets mires de contrôle IT8 IT8.7/1 Color transmission version, IT8.7/2 Color reflection version (both ISO 12641), IT8.7/3 Output test print format (ISO 12642; in Europe ECI2002 instead).

iteration itération step by step approximation to an ideal target; ICC profiles can also be improved in several iteration cycles, e.g. very elegantly with MMS Print Production Server.