JOSA, Journal of the Optical Society of America
What is JOSA, Journal of the Optical Society of America? JOSA, Journal of the Optical Society of America internationally leading technical journal for colorimetry.
JND, just noticeable difference
What is JND, just noticeable difference? JND, just noticeable difference (in French seuil de différenciation visuelle ) is brightness and/or chromaticness-related difference which is determined in so-called color threshold experiments (MacAdam ellipses); on the basis of thresholds determined in this way between “not noticeable” and “just noticeable difference”, perceptually equidistant color systems are constructed, e.g. CIELAB.
ICC, International Color Consortium
What is ICC, International Color Consortium? (ICC, International Color Consortium in French: 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…
Halftone
What is halftone? (Halftone in French: trame demi-ton) The opposite of continuous tone
Gamma
What is gamma? (Gamma in French: gamma) Gradation adjustment of a monitor; describes the relation of the decimal logarithm of the output to the input values (y = lg o / lg i), specifically of the RGB values of the input signal to the resulting luminances of the RGB monitor pixels. In Microsoft the value 2.2 is generated, from Apple OS X 10.6 also on the Macintosh, which up until this OS worked with 1.8….
Fastness property
What is fastness property? (Fastness property in French: solidité) Application oriented resistance of dried printing inks, toner and inks as well as colored foils to external influences; fastness property categories for printing inks according to DIN 16525: 1 “very low”, 2 “low”, 3 “moderate”, 4 “fairly good”, 5 “good”, 6 “very good”, 7 “excellent”, 8 “outstanding”; physical testing methods: Light fastness (ISO 12040: UV radiation), heat resistance (IR radiation); chemical testing methods (ISO 2836): Alkali…
“E” virtual illuminant E
What is “E” virtual illuminant E? “E” virtual illuminant E: achromatic point for the “equal energy point” with the arbitrary CIE chromaticity chart coordinates x = y = 1/3.
D50, artificial daylight 5000 K
What is D50, artificial daylight 5000 K? (D50, artificial daylight 5000 K in French: lumière artificielle 5000 K) Artificial daylight with a highly similar color temperature of 5003 Kelvin; standard CIE illuminant which was defined as standard in the printing industry in conjunction with the 2° standard observer field of view for the lighting conditions of printing inks, prints and proofs in color matching and at the central control console and as a white point…
“c”
What is “c”? “c” is the internationally used abbreviation for “color” in the sense of the number of colors that can be printed on a printing press in one run, e.b. 4c (four-color printing), 6c (4 process colors + 2 special colors), 4/4c (4 colors each in recto / verso printing, or top and bottom side of the web, or 4-color duplex digital printing).
Backing for Measurement
What is backing for measurement? (Backing for measurement in French: support de mesure) Surface standardized in hue (controversial: black or white) and reflection behavior (matt) which must be under a printed copy during the measurement of color or color density; black backing for measurement: absorbs light to prevent either a printed or an unprinted rear side from influencing the measuring results; this is why it is used in the printshop, for copies, OK sheets and…
Adjustment
What is Adjustment? (Adjustment in French: ajustement) The implementation of basic settings in measuring devices through exact positioning and internal value matching.
Adjacent
What is adjacent? (Adjacent in French: juxtaposition) Typical arrangement of two color matching samples in the field of vision to carry out the color comparison without the influence of contours and other surrounding colors.
Additives
What are additives? (Additives in French: additifs, adjuvants) Substances to influence the properties of printing inks, e.g. drying substances, antioxidants, waxes (for greater abrasive strength), plasticizers, flow agents (viscosity), anti-foam agents (for screen rollers), antistatic roller agents etc.
Additive Color Mixture/Synthesis
What is additive color mixture/synthesis? (Additive color mixture/synthesis in French: synthèse additive mixing principle of superimposing light colors through the addition of their components to form a color shade with greater brightness; primary colors Red-orange, Green), Blue-violet; secondary colors R+G=Yellow, R+B=Magenta, G+B=Cyan; maximum possible mixing result with sufficiently bright equal components is white, which is created by the addition of the primary colors W=R+G+B or of the two respective complementary colors W=R+C=G+M=B+Y; light colors are mixed…
Additive Color Mixing
What is additive color mixing? Example of superimposing red, green and blue spots. Pairwise superposition generates the secondary colors CMY, complete superposition leads to an achromatic shade (maximum: white).
Absorption-to-Scattering Ratio, A/S
What is absorption-to-scattering ratio, A/S? (absorption-to-scattering ratio, A/S in French: coefficient d’absorption et de diffusion, K/S basic equation developed in the 2-component theory of Kubelka and Munk in 1931 for the mixture of opaque color layers; ratio of A (concentration-dependent absorption degree of the color layer) to S (scatter behavior of the color layer, depending on the reflection degree R), calculated across the entire visible spectrum: For the Kubelka-Munk equation to be used for…
Absorption factor, Absorptance, Absorptivity
What is absorption factor, absorptance, absorptivity? (Absorption factor, absorptance, absorptivity in French: coefficient d’absorption, absorptivité) Ratio of absorbed to total incident radiant energy; may be applied as a curve α(λ) over the wavelength λ (spectral a.).
Absorption/Absorptive Attenuation
What is absorption/absorptive attenuation? (Absorption/absorptive attenuation in French: absorption) 1) lat. “suck in”; weakening (going as far as removal) of certain spectral components of the radiated light as it passes through a medium or strikes a brightly colored surface; through a., colored inks, printing inks and toners develop the desired colored effect; a. is responsible for “subtractive color mixing”; 2) absorption of ink by the substrate, leading to the drying of suitable printing ink layers.
Absolute White
What is absolute white? (Absolute White in French: standard/reference étalon blanc) Ceramic sample with completely matt white surface, whose known colorimetric values are used during calibration as a reference for spectral measuring devices; each color measurement by the device is then placed in relationship to the absolute white standard; the absolute white standard must be protected from dirt.
Abrasion/Rub Resistance
What is abrasion/rub resistance? (Abrasion/rub resistance in French: résistance à l’abrasion) Abrasion resistance of the dried printing ink layer or the overprint coating; necessary property of uncoated folding boxes and magazine covers.