Glossary of terms
Technical terms simply explained
backing for measurement 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 test prints for digital proof and high-circulation paper; white backing for measurement: during the acceptance of the characterization data (measuring of targets and test formes) on substrates and digital proof papers.
BAM, Federal Institute for Materials Research and Testing Institut fédéral pour la recherche et les essais des matériauxsenior German federal authority which prepares worldwide-recognized standards in the field of color through v a r i o u s DIN technical standards committees and which has developed several non-destructive measuring and testing methods (color, fluorescence, retroflection) which are used, among other things, for calibrating spectral densitometers.
bands bandes sensitivity ranges into which a spectral scanning head subdivides the spectral range to be measured; in portable devices, the width of a band (step width) is 1, 5, 10 or 20 nanometers.
Bandwidth largeur de bande wavelength range in which 1. light sources emit radiation, 2. radiation permeates filters (subdivision into “narrow-band” and “broad-band”).
basic colors couleurs de base see primary colors
basic stimulus stimulus de base the brightest achromatic point or chromaticity coordinates of the illuminant to light up in a color space or a chromaticity chart.
binder, binding agent/vehicle liant in printing ink, the carrier substance that surrounds the individual pigment particles and allows them to adhere to the substrate; is also responsible for viscosity and the drying mechanism; in offset, book and screen printing inks: resins (also UV-curing), drying/non-drying mineral and vegetable oils; in gravure and flexo printing inks: solvents, including water.
bit/color depth profondeur de pixel/d’échantillonnage number of lightness levels which a pixel can adopt; “bit depth” means the data depth in a color channel, e.g. “8 bits” means 8 bits per pixel (8 bpp) = 28 = 256 grayscales; “color depth” in an image file, on the other hand, means the number of color channels times pixel depth, “8 bits” then means = 28 × 1 = 256 grayscales, that is, a monochrome grayscale image; an RGB file has 28 × 3 = 224 = 16.7 million color shades (truecolor), a CMYK file 28 × 4 = 232 = 4.3 billion color shades. In the Photoshop CIELAB mode, it is still only possible to represent 8 bpp, so that 16-bit image data should be processed and forwarded using the RGB color space. In the hardware calibration of widegamut monitors, 10 bits are ideal for a detailed color space description.
bitmap fichier bitmap file that contains the coordinates of pixels with the relevant gray or color value, whereby all elements represented have the same image-related character, i.e. they are in pixel format; most important formats: JPEG, TIFF and all RAW formats see also Tables D-1 “Data file formats”
bits per pixel, bpp bits par pixel data depth with which one pixel per color channel is described; this gives the number of gray shades and color values that can be shown. Examples: 1 bpp = 21 = 2 tone values, i.e. line and screen graphics,
TIFF-G4 bitmaps (printing form separation data); 8 bpp = 28 = 256 gray levels, i.e. black-and-white images; 24 bpp for RGB = 8 bpp per color channel = 28 × 3 = 16.7
million colors (“True Color”), i.e. JPEG color images, color LUT; 32 bpp for CMYK = 8 bpp per color channel = 28 × 4 = 4.3 billion colors, i.e. images for four-color printing.
black body corps noir see Planckian radiator
black inks 1) encres noires black printing inks which unlike colored inks can have different grades of transparency, which is why different black formulations are often offered within the framework of a process color series. 2) couleurs foncés see
black, key noir process printing ink whose addition compensates for the spectral inadequacies of the chromatic colors CMY. Significance in achromatic and chromatic composition:
– “maximum black”: highest tone value that black can achieve in the image shadows (usually 95% in offset printing, seldom more);
– “starting point”: the tone value above which black replaces the chromatic colors;
– “short black”: supplements/replaces the chromatic colors in the dark tones only;
– “long black”: supplements/replaces the chromatic colors right as far as the highlights;
– “black length”: describes the black structure along the gray axis or L* axis (CIELAB);
– “black width”: specifies how far away from the gray or L* axis black supplements/replaces the chromatic colors; the greater the black width, the more black intervenes in the structure of higher chromaticness C* (CIELAB).
blackish/grayish drift assombrissement phenomenon of absorptive interference in which the linear increase of the proportion of a component leads less to a change in hue and mainly to a nonlinear brightness reduction.
blackness degré de noir in the sense of sensory color spaces, the achromatic tones of the CIELAB lightness axis L* between 0 and 50.
blend white blanc de mélange color mixing components brightening up through white pigments, see also opaque white, transparent white
blooming éblouissement blurring of the photographed object contours or extreme color variations on account of overexposure through an excessive amount of light; one reason for the replacement of CCD by CMOS sensors in digital photography.
blueness dominante bleue in the sense of opponent color theory, the hues in the blue area opposite to the yellow hues; representation as color space coordinates: b*<0 (CIELAB) and v’<0 (CIELUV). Each change in proportion in the printing of the
process colors CMYK leads to a change in blueness, so that the color that is responsible can only be detected technically and not visually; C, M and K increase B in different spectral ways. To this extent, unprofessional customer requirements within the framework of printing releases to the printing press, such as “a little more magenta and a little less yellow” lead to unpredictable changes in blueness; see also yellowness, greenness, redness.
brightening éclaircissement in the offset printing room the reduction of the color pigment content in the ink by adding transparent white or mixing white, in gravure and flexo printing by blending in the ink duct.
brightness luminosité synonym for the luminosity of a selfluminant body (light source, monitor).
brilliance brillant, brillance totality of subjective evaluation criteria such as luminosity, gloss, pigmentation, cleanness or contrast for the visual impression of a printed color surface; brilliance can be increased by applying a coat of paint or by
lamination.
bronzing bronzage dryback of colored ink, in particular special colors, into a reddish color.
browser navigateur software for retrieving and viewing multimedia-based Internet sites; the colors are coded in various “web color” models. Only a few standard browsers are capable of using ICC profiles, which is why they are currently used only as tools for selecting sites in high-quality soft copy proof applications.
black separation settings for a reduced total ink coverage (TIC) – 1. UCR with short, narrow black; 2. UCR + UCA with long, broad black; 3. medium GCR; 4. soft GCR (= CCR)
[Chart: Kleeberg]