Hairline RegisterPrinting registration that lies within the range of plus or minus one half row of dots. It is the thinnest of the standard printers' rules.
HalftoneTone graduated image composed of varying sized dots or lines, with equidistant centers.
Halftone PaperA high finish paper that is ideal for halftone printing.
Halftone ScreenA sheet of film or glass containing ruled right-angled lines, used to translate the full tone of a photo to the halftone dot image required for printing.
Hard DotThe effect in a photograph where a dot has such a small degree of halation that the dot shows quite sharp.
Head MarginThat space which lies between the top of the printed copy and the trimmed edge.
HickiesImperfections in presswork due to dirt on press, trapping errors, etc.
High Bulk PaperPaper stock that is comparatively thick in relation to its basis weight.
High Key HalftoneA halftone that is made utilizing only the highlight tones down through the middle tones.
Highlight DotThe highest density of a halftone image.
HighlightsThe lightest tones of a photo, printed halftone or illustration. In the finished halftone, these highlights are represented by the finest dots.
HollowThat space on the spine of a case bound book between the block of the book and the case binding.
Hot MeltAn adhesive used in the binding process, which requires heat for application.
House SheetThis is a term that refers to a paper that a printer keeps on hand in his shop.