halftone trame, demi-ton the opposite of continuous tone
halftone dot shape tramage variation of the AM halftone dot shape between circle/square/cushion/barrel and ellipse/ chain, to distribute the so-called dot touch (meeting of the square dot edges in medium tone 50%) among the quarter and three-quarter tones and thus to avoid tone value breaks; alternatively FM: random dot size and distribution to avoid annoying patterns (moiré). The halftone dot shape has a significant influence on color rendering and is one of the parameters which, if changed, causes an ICC profile to lose its validity.
hard copy proof épreuve papier 1) all physically output test prints – unlike soft copy proof, which is only output on a color monitor; 2) printout printed on a linearized and ICC-profiled inkjet printer, simulating the results in the target printing process; possible requirements; contract-proofed and/or screen-proofed.
hardware calibration calibrage de l’écran calibration of a wide-gamut monitor according to certain target values; can be carried out far more precisely than a software calibration. The correction entries are effected directly in the monitor’s own color table (hardware LUT), e.g. with NEC with an accuracy of 14 bit = 16384 basic values. The LUT of the graphics card remains unaffected, which means that the video signal is not restricted and the color dynamics scope remains at the highest possible level. Each color channel can also be assigned an individual tone reproduction curve (TRC). The calibration operation itself is carried out with the help of a monitor colorimeter, e.g. basICColor Discus, which is in a position to measure not only directly on the screen but also at the usual viewing distance and considering the lightness of cabin and surrounding.
HDR, high dynamic range photography photographie à grande gamme dynamique unnaturally overmodulated contrasting in photographs; identical but differently exposed motifs are calculated together in special programs according to selectable algorithms to form an image; besides JPEG and TIFF, HDR formats are also written, e.g. HDRI or OpenEXR.
heatset inks encres heatset printing inks for rotary offset presses with hot air drying; the binding agents contain special mineral oils which evaporate and vaporize when exposed to hot air and which are made to match the substrate (coated or uncoated) or to withstand abrasion. The drying status that can be achieved is determined by the dwell time and the temperature conditions in the hot-air dryer.
hiding ability, opacity couvrant, couvrabilité ability of print printing ink, formerly designated as covering ability/power, to cover the structure and hue of the substrate more or less well. The necessary minimum coating thickness is described in accordance with DIN 55943 with the covering ability value Dv (in m²/l) for the volume of liquid printing ink and Dm (in m²/kg) for the mass of dried inks, whereby a defined surface must be covered. Opposites: glazing ability, transparency
high fidelity color HiFi-Color multicolor printing in which the darkened CMY mixed colors RGB are replaced by independent color separation files/prints, which makes it possible to print true RGB tones. During color separation, the RGB printing inks are replaced with the CMY screen angles; the best-known high fidelity system for offset printing is Pantone Hexachrome, the furthest developed is ederMCS with several CMY and RGB tones. See also Küppers color theorie on pages 62 (explanation) and 15 (history).
high-key image image claire/surexposée low-contrast image which only shows patterns in the quarter tones (high-light range) and therefore appears very light; in printing highly prone to fluctuations in color balance.
highlights, light tones hautes lumières tone range 0 to 30% (quarter tones).
histogram histogramme frequency distribution of the tone values in a bitmap image; can be viewed and edited in every better image processing program, e.g. for increasing contrast (through spread) and white alignment.
HKS color guide nuancier HKS system jointly developed by the German manufacturers Hostmann-Steinberg (Huber group), K+E (Flint Group) and Schmincke Künstlerfarben for selecting special colors, which are provided by the manufacturers/trading partners as required as pure mixtures or can be mixed by the printers themselves from 9 basic colors + black and white. The color guides contain 88 basic colors, in the “3000+” version 3520 intuitive grades (88 × 40 shades), each with information on trueness, mixing recipe and best possible CMYK approximation as well as examples of color and contrast effects; substrates: “K” (art printing) (ink film thickness 1.5 g/m²) and “N” (natu – ral) (2 g/m²) as well as “Z” (newspaper), “En” (endless natu – ral) and “Ek” (endless matt coated) with 1.2 to 1.4 g/m²; digital products: HKS color library is used as standard in Techkon spectrodensitometers, plug-ins for Adobe CS and QuarkXPress, 97 web colors (hexadecimal).
holographic inks encres holographiques printing inks with added aluminum reflecting particles, which show typical hologram (rainbow-like) and other lustrous effects. In conjunction with ready-made hologram graphics files, embossed holograms can be imitated. Examples of suppliers: Avery Dennison Metalure/Eckart Topstar (offset), Excalibur Glitter (screen printing), Flint HIP (UV flexo); on account of its suitability for security printing, usually only available for registered users.
holography holographie photography that allows the spatial reproduction of a scene in a special recording medium. For color holography, single-color laser beams in the colors RGB are directed onto the scene to be reproduced; the reflected and scattered light form a wave pattern which, together with the original beams, forms a common interference pattern, which is then recorded photographically. This hologram develops
its 3D effect in all light whose spectrum contains sufficient red, green and blue components.
horse shoe fer à cheval see CIE chromaticity chart
HSB,HSI, HSL, HSV, HVC see intuitive
hue teinte, tonalité chromatique standard designation for “tint”.
hue angle angle de teinte coordinate hab in the intuitive L*C*hab coordinate system (brightness, chromaticness, hue angle) of the CIELAB color space; representation as angle hab = arctan (b* / a*) = 0 … 360° in the CIELAB color circle; same meaning in the CIELUV system.
hybrid printing impression hybride technologies developed and optimized by KBA; 1. in sheet-fed offset, printing with hybrid inks (oxidation-drying and UV curing, without dispersion primer UV varnishable, unusual gloss contrast effects) on glossy and matt-coated substrates; 2. on the KBA Cortina newspaper and supplement printing without ink change with coldset waterless offset inks with unchanged dot gain, whereby the supplement web runs through a heatset hot-air dryer – an alternative to supplement printing with coldset inks without heatset dryer and with changed dot gain (FM screen, improved newspaper paper).