H

Hexachrome

The Hexachrome printing process uses a a color model based on six primary colors as opposed to the traditional four color process. As well as cyan, magenta, yellow and black, Hexachrome also adds orange and green into the range. To utilise the six colors, images must be scanned and imported using software that can understand the file formats, which most up to date DTP graphics software can.

Orange and green are the hardest colors to reproduce in vibrant shades using the traditional CMYK four color process and so Hexachrome is used when an extremely high print quality color reproduction is required. The downside is that it is generally far more expensive at the prepress and print production stages.

Histogram

An electronic tool in Photoshop and other image editors, that shows the relative distribution of the density of pixels in a scan. It is used to gauge the evenness of distribution of shadow and highlight tones in scanned digital images.

Hot metal typesetting

Hot metal (or hot lead) typesetting, linecasting or compositing is a no-longer used method of setting lines of type for printing on a letterpress printing machine.

Initially this was done by hand, where the typesetter would either set individual letter or slugs of type. Eventually machines were built that speeded up this process somewhat. The most famous exponents of hot metal were Linotype and Monotype, who have recently merged into one company.

Hot metal typesetting was eventually replaced by Phototypesetting and, later on, desktop publishing.