# stixfonts OpenType Unicode fonts for Scientific, Technical, and Mathematical texts ## About the STIX fonts. See https://www.stixfonts.org/ for background on the the STIX Fonts project. The Scientific and Technical Information eXchange (STIX) fonts are intended to meet the demanding needs of authors, publishers, printers, and others in the scientific, medical, and technical fields. They combine a comprehensive Unicode-based collection of mathematical symbols and alphabets with a set of text faces suitable for professional publishing. They are available royalty-free under the SIL Open Font License, Version 1.1. Version 2 of the STIX fonts, now known as “STIX Two”, is a thorough revision of version 1 undertaken by the renowned type house [Tiro Typeworks](https://tiro.com). The STIX Two fonts consist of four text fonts (Regular, Italic, Bold, and Bold Italic) and one Math font. Together, they provide a uniform set of fonts that can be used throughout the production process, whether that be a traditional print-only process, an entirely electronic one, or a combination of the two. The [STIX project](https://www.stixfonts.org/) began through the joint efforts of the [American Mathematical Society](https://www.ams.org/) (AMS), the [American Institute of Physics](https://www.aip.org/) (AIP), the [American Physical Society](https://www.aps.org/) (APS), the [American Chemical Society](https://www.acs.org/) (ACS), the [Institute of Electrical and Electronic](https://www.ieee.org/) Engineers (IEEE), and [Elsevier](https://www.elsevier.com/). These companies are collectively known as the STI Pub companies. ### A Fresh Take on Times Roman The original version of STIX was based on Times Roman, which has now been updated for the digital age. As is well known, Times Roman was originally intended for printing the *London Times*. What is not generally appreciated is that the production quality of the *Times* was atypically high: It was printed on unusually high-quality paper on presses that operated more slowly than most newspaper presses. This allowed for the design of a typeface that could exploit this level of care: serifs could be much finer and counters (enclosed areas such as that in the lowercase *e*) could be much smaller than in other newspaper typefaces. These features of the font have not always fared well in less exacting environments. At the same time, a notable quirk of the Times Roman family is that the bold font is, in many respects, strikingly dissimilar to the roman font. Tiro Typeworks explain their approach to updating the Times Roman basis of STIX as follows: > “Our principal goal in approaching STIX Two was to address several > inherent deficiencies in the Times New Roman model as well as expand > the typographic features. This process necessarily involved > diverging somewhat from Times as familiar to people who have only > known the common digital versions, while simultaneously restoring to > that typeface aspects of the size-appropriate design characteristics > that made it so successful in newspaper, book, and journal > publishing in it’s metal type incarnation. The essential > ‘Times-ness’ remains, but are with greater harmonisation of style > across the family. > > “Most digital versions of Times have been based on an optical size > model that appears too light and fine when scaled down to typical > text sizes. In the design of STIX Two, we went back to specimens of > size-specific designs from the metal era, and adapted proportions, > weights, and spacing of the 10pt and 12pt designs. The oft-noted > mismatch between the style of different weights of Times has been > resolved with a new bold design that matches the construction of the > regular weight.” ### Font implementation decisions * The STIX fonts do not contain fixed-width or sans serif text faces. * The sans serif, fraktur, script, etc., alphabets in Plane 1 (U+1D400-U+1D4FF) are intended to be used only as technical symbols. * These fonts are designed to support left-to-right typesetting in Latin-based scripts, with additional support for Greek and Cyrillic text. Extensions to support other writing directions have been considered, but are currently deemed to be outside the scope of the STIX project. ### Note to TeX users These fonts have been tested with both [XeTeX](http://xetex.sourceforge.net/) and [luaTeX](http://www.luatex.org/) with good results. For best results, XeTeX users will want to use version 0.99999 or later of XeTeX, which ships with [TeXLive 2018](https://www.tug.org/texlive/). This version fixes a number of bugs that were present in earlier versions. Our thanks go out to Jonathan Kew and Khaled Hosny for their generous help in identifying and fixing these bugs. LaTeX users should also make sure they have the latest version of the [amsmath package](https://ctan.org/pkg/amsmath). ## Summary of OpenType Features and Scripts Further details these features can be found in the code charts. The four text fonts implement the following OpenType script tags: Regular Bold Italic BoldItalic DFLT DFLT DFLT DFLT Default cyrl cyrl cyrl cyrl Cyrillic cyrl.MKD cyrl.MKD Cyrillic/Macedonian cyrl.SRB cyrl.SRB Cyrillic/Serbian grek grek grek grek Greek latn latn latn latn Latin latn.ROM latn.ROM latn.ROM latn.ROM Latin/Romanian latn.TRK latn.TRK latn.TRK latn.TRK Latin/Turkish and the following features c2sc Small Capitals from Capitals case Case-Sensitive Forms ccmp Glyph Composition/Decomposition dnom Denominators frac Fractions kern Kerning liga Standard Ligatures -- latn only locl Localized Forms -- latn.ROM and Italic/BoldItalic cyrl.MKD only numr Numerators onum Oldstyle Figures pnum Proportional Figures smcp Small Capitals subs Subscript sups Superscript All four text fonts also support the following Character Variants: cv01 U+019B Lambda with horizontal, not slanted stroke -- latn only cv02 U+0264 Rams horn with serifs -- latn only cv03 U+2423 OPEN BOX curved instead of straight In addition, the Italic and BoldItalic faces support the following Stylistic Variants: ss01 Replace two-story g by hooked g -- Italic/BoldItalic only ss02 Upright parens, brackets, and braces -- Italic/BoldItalic only STIX Two Math implements the following font features: ccmp Glyph Composition/Decomposition dtls Dotless forms of i and j flac Flattened accents ssty Math Script style alternates and the following Character Variant (note the different meaning compared to the text fonts): cv03 Replace U2205 EMPTY SET by an oblate form and the following Stylistic Sets (again, note that ss01 and ss02 have different meanings compared to the text fonts): ss01 Stylistic Set 1 -- Math chancery to roundhand (\mathcal -> \mathscr) ss02 Stylistic Set 2 -- Alternate italic forms: g, u, v, w, z ss03 Stylistic Set 3 -- Horizontal crossbar variants ss04 Stylistic Set 4 -- Minute, second and primes to long variants ss05 Stylistic Set 5 -- Short arrow variants ss06 Stylistic Set 6 -- Short/narrow variants ss07 Stylistic Set 7 -- Alternate math symbols (product, summation, etc) ss08 Stylistic Set 8 -- Upright integral variants; XITS compatible ss09 Stylistic Set 9 -- Vertical slash variants; XITS compatible ss10 Stylistic Set 10 -- Diagonal greater/lesser combination variants ss11 Stylistic Set 11 -- Long slash not-equal combination variants ss12 Stylistic Set 12 -- Low contrast (sans-like) variants ss13 Stylistic Set 13 -- Horizontally flipped sine wave glyph ss14 Stylistic Set 14 -- Tall variants ss15 Stylistic Set 15 -- Slab serif symbol variants ss16 Stylistic Set 16 -- Circled operator variants ss20 Stylistic Set 20 -- Miscellaneous variants