OpenType Typography Support in LibreOffice

LibreOffice provides extensive support for advanced OpenType typographic features, including standard and discretionary ligatures, true small capitals, contextual alternates, fractions, and numeric styles. Powered by the HarfBuzz text-shaping engine, LibreOffice allows users to unlock these professional typesetting capabilities in any font that contains the corresponding OpenType tables.

How to Access OpenType Features in LibreOffice

Users can enable OpenType features in LibreOffice Writer through two primary methods:

  1. The Font Features Dialog: Navigate to Format > Character > Font tab and click the Features button to toggle available OpenType options via a graphical interface.
  2. Font Name Syntax: Append feature tags directly to the font name in the font box using the format FontName:feature_tag=value (for example, Linux Libertine G:smcp=1&liga=1).

Key OpenType Features Supported

1. Ligatures

LibreOffice supports multiple ligature categories to prevent awkward character collisions and improve text flow: * Standard Ligatures (liga): Common character combinations such as “fi”, “fl”, “ff”, and “ffi”. * Discretionary Ligatures (dlig): Decorative pairings such as “st”, “ct”, and “Th”. * Historical Ligatures (hlig): Archaic glyph combinations used in vintage typesetting. * Contextual Ligatures (clig): Ligatures applied based on surrounding text context.

2. Small Capitals and Capital Forms

Instead of artificially scaling down full capitals, LibreOffice accesses native, proportionally designed small caps: * Small Capitals (smcp): Converts lowercase letters into true small caps. * Capitals to Small Capitals (c2sc): Converts uppercase letters into small caps for uniform acronym styling. * Petite Caps (pcap): Smaller than standard small caps, scaled to match the font’s x-height.

3. Numerical and Figure Styles

LibreOffice enables precise control over how numbers are rendered: * Proportional Figures (pnum): Numerals with variable widths for use in body text. * Tabular Figures (tnum): Monospaced numerals aligned vertically for tables and financial documents. * Oldstyle Figures (onum): Numbers with varying heights and descenders that blend seamlessly into lowercase body copy. * Lining Figures (lnum): Modern, uniform-height numerals matching uppercase letters. * Fractions (frac): Automatically renders diagonal fractions (such as 1/2 or 3/4) using specialized numerator and denominator glyphs. * Slashed Zero (zero): Replaces standard zeros with slashed versions to distinguish them from the letter “O”.

4. Stylistic Sets and Character Variants

Many modern typefaces include alternate character designs accessible via LibreOffice: * Stylistic Sets (ss01 through ss20): Groups of stylistic variations designed to give the overall typeface a distinct tone. * Character Variants (cv01 through cv99): Target specific individual letters to select alternate glyph shapes. * Swashes (swsh) and Contextual Alternates (calt): Flourishes and dynamic letter adjustments based on character position in a word.

5. Additional Typographic Controls