overlap print (In French repiquage, surimpression superimposition) of the halftone dots during combined printing of the process printing inks.

output targeting (In French calibrage de sortie (description de la caractéristique)) recording of so-called characterization data by the spectrophotometrical measuring of a prescribed test chart (e.g. ECI 2002) with the support of a setpoint value-measured value assignment application, e.g. basICColor catch pro; ICC profiles can be calculated from the characterization data; the device properties are characterized taking account of thematerials used (paper, toner, ink, blanket), settings (impression setting, screen model / ruling) and general conditions…

Output Intent (In French intention/mode de sortie) in a PDF file, the specification of the intended printing conditions including characterization data, e.g. “ISO coated v2” (see Tables C-1 “Characterization data of printing processes” on page 26), not to be confused with a rendering intent. The ICC profile of this printing condition must be either saved as well or linked to a characterization file.

output device (In French unité de sortie) in the sense of ICC, all devices that output in accordance with the CMYK color model or special colors (color printers, printing presses) or RGB (photo laboratory systems).

out-of-home media (In French publicité extérieure) group of highly differing media with a high color effect; printed (CMYK): placards, posters, stickers; electronic (RGB): LED video boards (including stadium banners), projection screens, electro-luminescent displays (conductive, self-illuminating foils integrated in glazed advertising spaces and show motifs of simple animations), LCD monitors (in public transport). All of these media can be integrated in a direct living environment (“ambient media”).

out-of-gamut warning (In French alarme de gamut/gamme) function in software conforming to ICC to warn of colors outside the color space; the warning is intended to avoid errors of leaving outof- gamut colors (couleurs hors gamut) in output files without having subjected them to gamut mapping.

out-of-gamut color (In French couleur hors gamut) see gamut mapping

OSA Color System (In French système chromatique) OSA color ordering system developed by the Optical Society of America in 1976; the color space structure of its 588 color samples follow the CIELAB system, which was passed at the same time. Lightness L from +5 (white) to –7 (black), redness-greenness g from +6 (red) to –10 (green), yellowness-blueness j from +11 (yellow) to –6 (blue); defined for D65 and 2°/10°.

optimal color (In French stimulus de couleur) optimaux surface color whose color impression is created from the mixture of 100% light spectral colors. An optimal color (W. Ostwald: “full color” is thus the lightest possible and most saturated color of this chromaticity, and there is only this one optimal color for this one chromaticity. On account of the 100% level of the spectral colors, the curve of its spectral luminance factor does not have a…

optical/fluorescent brightening/whitening agent (OBA, FBA, FWA), whitener (In French azurant optique, agent azurant/fluorescent/ de blanchiment) substances that convert the invisible UV components of incident light into visible wavelengths to make paper appear even whiter. The bluish brightening effect is complementary to the yellowish, not completely white-bleached paper components. In ICC color management, FWAs make the visual correspondence between digital proof and production print more difficult. For this reason, when recording the characterization data for ICC…

opponent color theory (In French théorie des couleurs opposées) theory of color signal processing in the brain, established in 1905 by E. Hering and attributed in 1927 by R. Luther to the basic stimuli PDT (today LMS). According to this theory, the spectral value function signals obtained from the cone types generating green (P, M), red (D,L) and blue (T, S) are further processed neither in their original form nor as RGB signals, but are…

optimal colors top down: “midwave color” green, “out of midwave color” magenta, “shortwave end color” blue, “longwave end color” red. [Chart: Kleeberg]

opaque white (In French blanc couvrant) white printing ink with high covering ability; white pigments are mixtures of zinc sulphide and barium sulphate as well as expensive titanium dioxide; opaque white is applied as a white undercoat on transparent or insufficiently white substrates, including data carriers.

opaque (In French opaque) property of bodies not to be transparent or translucent. The thinner a paper, the less opaque.

opacity (In French opacité) measure for the opaqueness or lightproofness of unprinted and printed materials. The opacity of paper is increased by adding wood and filler substances.

on-light/reflected light measurement (In French mesure en lumière réfléchie) measurement setup for measuring the color and color density of inks, prints and reflection copy; measure ment geometries lamp-on-sample/sample-on-detector: aligned 45° 0° gloss-free or aligned 0° 45° gloss-free or diffuse/8°.

offset/litho[graphic][printing] inks (In French encres (d’impression)) offset printing inks ranging from highly viscous-pasty consistency (sheet-fed offset, long-grain rotary offset, heatset) to low-viscosity liquid consistency (coldset) and noticeable stickiness; available with numerous drying principles, drying and tackiness settings, truenesses and mechanical properties, depending on the substrate and intended use of the printed product; the main components are organic/inorganic pigments, binding agents (resins dissolved in mineral and vegetable oils), auxiliary substances (waxes, drying substances, in some cases…

off-press proof (In French épreuve analogique) proof obtained by means of separation films and pigment transfer films; on account of modern filmless processes this has been pushed into a niche (simulation of special pigment effects in packaging printing) by digital proofs.

odorless, low/mild odor (In French à faible odeur) required sensor properties of printing inks for food and tobacco secondary packaging (folding paper boxes); odor development goes along with influence on taste; see low-migration.