OTF, short for OpenType Font, is the extension of OpenType font files whose outlines are described in PostScript using cubic Bézier curves. It is now the standard format for print and graphic design.
Where to see it
OTF is recognizable by the .otf extension of the files most foundries deliver with a desktop license. It is also the format of fonts installed through Adobe Fonts for use in design software.
Why this detail matters
Knowing how to recognize an OTF file helps you choose the right format for each use:
- Its cubic Bézier curves, the same as in Illustrator, faithfully render the design of the letters, which makes it the preferred format for print;
- Like any OpenType file, it gives access to the font's advanced features: ligatures, small caps, alternates and oldstyle figures;
- For a website, it is not used directly: it is converted to the lighter WOFF2, after checking that the license allows this use.
Related term
TTF is the other major font format, whose outlines are described by quadratic curves and which allows very precise hinting.