Editing Typographic unit (section)

{{Short description|Units of measurement}}
{{More footnotes|date=June 2023}}
{| style="float: right; border: 1px solid #BBB"
| style="width: 220px;" | [[File:The Evening Star ruler - 3.jpg|210px]] [[File:The Evening Star ruler - 2.jpg|210px]]
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| A ruler showing 4 scales (from the top down): [[Inch]]es, [[Point (typography)|Points]], [[Pica (typography)|Pica]]s, and [[Agate (typography)|Agates]]
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[[File:Font metrics.svg|thumb|right|Diagram of font metrics showing where letters and symbols would be placed relative to each other. The letters would change size according to the font type, typographic unit and dimension used.]]
'''Typographic units''' are the units of measurement used in [[typography]] or [[typesetting]]. Traditional [[wikt:typometry|typometry]] units are different from familiar [[SI|metric]] units because they were established in the early days of printing. Though most printing is digital now, the old terms and units have persisted.

Even though these units are all very small, across a line of print they add up quickly. Confusions such as resetting text originally in type of one unit in type of another will result in words moving from one line to the next, resulting in all sorts of typesetting errors (viz. [[River (typography)|rivers]], [[widows and orphans]], disrupted tables, and misplaced captions). Before the popularization of [[desktop publishing]], type measurements were done with a tool called a [[typometer]].<ref>{{cite book |last1=Radics |first1=Vilmos |last2=Ritter |first2=Aladár |year=1984 |title=Make-up and typography |url=https://books.google.com/books?id=yx3sAAAAMAAJ |access-date=25 November 2016|language=English |publisher=International Organization of Journalists |page=13 |isbn=9789630231367 |quote=The typometer is an instrument for measuring typographical denominations: type sizes, column width and depth, slugs, type area, etc.}}</ref>