Editing Halftone (section)

{{Short description|Printing process}}
{{About|the graphic technique|the musical interval|Semitone|the musical note|Half note}}
{{use mdy dates|date=March 2022}}
[[File:Halftoning introduction.svg|frame|Left: Halftone dots. Right: Example of how the human eye would see the dots from a sufficient distance.]]

'''Halftone''' is the [[reprographic]] technique that simulates [[continuous tone|continuous-tone]] imagery through the use of dots, varying either in size or in spacing, thus generating a gradient-like effect.<ref name="campbell">Campbell, Alastair. ''The Designer's Lexicon''. ©2000 Chronicle, San Francisco.</ref> "Halftone" can also be used to refer specifically to the image that is produced by this process.<ref name="campbell"/>

Where continuous-tone imagery contains an infinite range of [[color]]s or [[grey]]s, the halftone process reduces visual reproductions to an image that is printed with only one color of ink, in dots of differing size ([[pulse-width modulation]]) or spacing ([[frequency modulation]]) or both. This reproduction relies on a basic [[optical illusion]]: when the halftone dots are small, the human eye interprets the patterned areas as if they were smooth tones. At a microscopic level, developed black-and-white photographic film also consists of only two colors, and not an infinite range of continuous tones. For details, see [[film grain]].

Just as [[color photography]] evolved with the addition of [[optical filter|filters]] and film layers, color printing is made possible by repeating the halftone process for each [[subtractive color]] – most commonly using what is called the "[[CMYK color model]]".<ref name="mccue">McCue, Claudia. ''Real World Print Production''. ©2007, Peachpit Berkeley.</ref> The semi-opaque property of [[ink]] allows halftone dots of different colors to create another optical effect:  full-color imagery.<ref name="campbell"/> Since the location of the individual dots cannot be determined exactly, the dots partially overlap leading to a combination of additive and subtractive color mixing called ''autotypical color mixing''.