printing ink sequence (In French ordre d’impression des couleurs, séquence des couleurs) in multicolor printing, the sequence of the printing of the process colors or other chromatic colors on the substrate; the standard offset printing process prescribes KCMY for sheet-fed offset, heatset and long grain web offset; deviations are possible, for example with scales with picking susceptibility. Coldset newspaper printing prefers CMYK, less frequently KMCY. Reason: different ink absorbency properties of the papers and wet-in-wet…

printing ink (In French encre d’impression) pasty-viscous to watery mixture of color agents, film formation agents and possibly also solvents, auxiliary materials and additives. The purpose of printing ink is to achieve light-dark and or colored contrasts on the substrate. Depending on the printing process (printing ink transfer, in offset printing also the wet and waterless wetting principles) and absorbency of the substrate surface (ink absorption capacity) the stable adhesion of the color agents is…

printability (In French imprimabilité) suitability of a substrate for a printing process all mechanical, optical and thermal properties of a substrate that are relevant for the interactions with the ink, in particular smoothness, absorptive capacity, oil absorption, pick strength, surface tension and pH-value.

print run paper/stock (In French papier du tirage) the print stock identical to the print run, whose color coordinates (“paper white”) are to be simulated in the color workflow.

print quality (In French qualité d’impression) grade of printed image reproduction, depending above all from the interaction between printing ink and substrate; quality control takes place in all phases of the print value-added chain, whereby it is also possible to observe the quality status via the Internet as well as over long periods of time (“quality monitoring”, e.g. iQIP by impakt medien).

primary stimuli, primaries (In French stimulus de couleur de référence) mathematical model for the value-based identification of a color stimulus in additive color mixing; derived from the basic stimuli of the 3 cone types, the real color stimuli R, G, B characterize the color signal absorption in the 3 color channels of the eye; CIE(1931) definitions of the primary stimulus wavelengths λ and the related relative spectral radiation distribution S(λ) for the equi-energy spectrum (illuminant…

primary source (In French source primaire) see light source.

(primary) color channel (In French canal couleur) component for representing color information in scanners, digital cameras, monitors (RGB) and graphic data formats (RGB, CMYK).

primary/basic colors (In French couleurs primaires) arbitrarily chosen color shades, from the mixture of which other random color shades are to be created; primary colors in additive color mixing: R, G, B; primary colors in physical color mixing: C, M, Y.

press proof (In French épreuve machine) an individual color separation and associated combined print of the color separation produced on a press proof machine (in particular sheet-fed gravure); is gaining importance again for complicated color printed products to rule out metamerism phenomena in the original pigments.

ppi, pixels per inch (In French pixels par pouce) see definition.

PPF, print production format see CIP4.

poster inks (In French encres pour impression d’affiches) sheet-fed offset inks with high light fastness and fast oxidative drying through.

polarizing filter, polarizer, polaroid (In French filtre polarisant) filter which allows radiant or reflected light to pass only in one oscillation direction of the wavelengths; application: prescribed (except for USA) in densitometric measurement to be able to eliminate differences in gloss between wet ink immediately after printing and dried printing ink; optional for color measurements on metallic color prints.

point of smearing (In French limite de graissage) desirable offset printing setting of the ink-dampening solution balance, in which as little water as possible is used to keep the non-printing gaps just free of ink, that is, at the limit of scumming; which conversely means over-inking (smearing); opposite: water marks.

Planckian radiator, black body (In French radiateur de Planck, corps noir) ideal hollow body which completely absorbs light reaching it through a small opening, and which thus heats up and glows. As the temperature rises, the glow passes through various luminescent colors (see color temperature); this curve is marked in the CIE chromaticity chart as Planckian locus.

pixel graphics file (In French image matricielle/en mode point) simulation of a continuous halftone image composed of elements (pixels) arranged as in a halftone screen; disadvantage: when the scale is changed, interpolation pixels are created between the original pixels, and these have an adverse effect on sharpness and color rendering.

pixel, picture element (In French pixel) 1) smallest addressable component of an image file with a certain data depth (see bit depth). The pixel size corresponds to the size of the sensors or recording resolution in the input devices and can lead to aliasing when describing contours. 2) image element of an active matrix display, in which however the RGB subpixels are the smallest addressable components.

pigments (In French pigments) natural or synthetic, organic or inorganic color agents which are incorporated as powders or pastes in binding agents for paints and printing inks as well as inkjet inks, in which they are practically insoluble. Unlike coloring dyes, they have a coloring-through effect, i.e. they provide not only chromaticity coordinates but also a degree of opacity. Approx. 600 pigments are classified in the Color Index. Process color pigments: beta-phthalocyanine blue BN (C),…

pigmentation (In French pigmentation) categories for printing inks: “normal” (standard scales) and “high” (intensive scales).