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Hairline (Rule) In typography, a very thin rule line typically less than one-half point wide. On some output devices, the hairline rule is as thin as the smallest printer spot the device can image. On 600 ppi laser printers, the hairline rule is effective; however, on high-resolution (2400+ ppi) imagesetters, it can be essentially invisible. |
| Half-scale Black Black separation made to have dots only in the shadows and midtones, as compared to full-scale black and skeleton black. |
Halftone The reprographic technique that simulates continuous tone imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect. "Halftone" can also be used to refer specifically to the image that is produced by this process.
Where continuous tone imagery contains an infinite range of colors or greys, the halftone process reduces visual reproductions to an image that is printed with only one color of ink, in dots of differing size or spacing. This reproduction relies on a basic optical illusion: the tiny halftone dots are blended into smooth tones by the human eye. |
| Hardcover Rigid protective covers (typically of cardboard covered with buckram or other cloth, heavy paper, or occasionally leather) of a book. |
| Head-to-tail Imposition with heads (tops) of pages facing tails (bottoms) of other pages. |
| Header A separate bit of text at the top of a printed page. |
| Heat-set Web printing A printing process in which ink is dried rapidly by forced-air heating. In the alternative method, coldset Web offset printing, the ink dries more slowly by ordinary evaporation and absorption. Web offset printing is a printing process in which a continuous roll of paper is fed through a printing press. |
Hectograph A printing process that involves transfer of an original, prepared with special inks, to a pan of gelatin or a gelatin pad pulled tight on a metal frame.
While the original use of the technology has diminished, it has recently been revived for use in the art world. The hectograph has been modernized and made practical for anyone to use. While the hectograph process is obsolete for printing on paper, it is still used for making temporary tattoos on human skin. It is also used to create unique acrylic paint prints. |
| Hickey Any printing defect caused by a particle either of paper or other source of debris attaching itself to the printing plate, blanket, gravure cylinder, or other image-carrying surface. |
| High-fidelity Color Color reproduced using six, eight or twelve separations, as compared to four-color process. |
| High-key Photograpy A modern lighting technique that is based on using mid-tone greys through to bright whites. The use of bright lights and lighting to eliminate shadow reduced the contrasts in the picture. |
| Highlight An area or a spot in a drawing, painting, or photograph that is strongly illuminated. |
| HLS HSL stands for hue, saturation, and lightness (or luminosity),and it is one of the two most common cylindrical-coordinate representations of points in an RGB color model. Developed in the 1970s for computer graphics applications, HSL is today used in color pickers, in image editing software, and less commonly in image analysis and computer vision. |
| Hot metal typesetting In printing and typography, it refers to technologies for typesetting text in letterpress printing. This method injects molten type metal into a mold that has the shape of one or more glyphs. The resulting sorts and slugs are later used to press ink onto paper. |
