Hairline register Register within ±1/2 row of dots.

Halftone The reproduction of continuous-tone images, through a special screening process, that converts the image into dots of various sizes and equal spacing between centers (AM or Amplitude Modulated screening), or dots of equal size with variable spacing between them (FM or Frequency Modulated screening), or some combination of them.

Hard copy The permanent visual record of the output of a computer or printer on a substrate. "Soft" copy refers to images displayed on screens.

Hard dot Halftone dot with little or no fringe and prints with little or no dot gain or sharpening. See soft dot.

Hard proof A proof on paper or other substrate as distinguished from a soft proof that is an image on a screen.

Hardware Computer and peripherals as distinguished from software, that is a program for operating hardware.

Head margin The white space above the first line on a page.

Hickeys In offset lithography, spots or imperfections in the printing due to dirt on the press, dried ink skin, paper particles, etc.

High contrast A reproduction with high gamma in which the difference in darkness (density) between neighboring areas is greater than in the original.

Highlight The lightest or whitest parts in a photograph or digital image represented in a halftone reproduction by the smallest dots or the absence of dots

Holdout A property of coated paper with low ink absorption that allows ink to set on the surface with high gloss. Papers with too much holdout may transfer ink to other sheets.

HSV Acronym for hue, saturation, and value (or brilliance or luminance) - a color space used in some graphic programs.

HTML (HyperText Markup Language) In imaging for the World Wide Web, the coding language that is used to create Hypertext documents for use on the World Wide Web.

Hue In color, the main attribute of a color that distinguishes it from other colors.

Hydrophilic Water receptive Non-image areas, for example, on an offset plate, "love" water. The opposite is hydrophobic.

Hydrophobic Water repellent Image areas, for example, on an offset plate, "hate" water. The opposite is hydrophilic.

Hypertext Links to other documents. Words or phrases in the document that are so defined that they can be selected and then cause another document to be retrieved, opened, and displayed. Links to other websites are also definable.