OpenType

Also called OTF, OpenType features, otf

The font format in universal use since the late 1990s, holding either TrueType or PostScript/CFF outlines in one file, Unicode-mapped, cross-platform, and — the part designers care about — carrying layout tables. GSUB substitutes glyphs, GPOS positions them; between them they drive ligatures, small caps, figure sets, alternates and kerning.

Five rows, each labelled with its four-letter OpenType tag and showing what that tag produces — the result only, not a default beside it, since an SVG cannot switch GSUB on. liga sets Georgia's real ﬁ and ﬄ glyphs. smcp sets NASA in Georgia Bold at x-height, noted as a stand-in because no small-cap glyph is reachable. onum sets 0123456789 in Georgia's own figures, which are oldstyle by default — 6 and 8 ascend, 3 4 5 7 9 drop. tnum sets 1,141.00 with every figure on one 0.614 em advance. swsh sets a plain Q and R, noted as unreachable.

In practice

"OpenType features" in a specimen means the GSUB/GPOS tags: liga, dlig, smcp, onum, tnum, swsh. In CSS, reach for font-variant-* first and font-feature-settings only when there's no property for what you need.

Not to be confused with

Variable fontAn OpenType font holding a continuous design space rather than fixed instances: master outlines plus deltas, interpolated at render time along one or more axes. One file can replace a dozen static weights at a fraction of the bytes, and gives every value between the masters — 437 as readily as 400 or 500.

How this term connects

Related Confused with

In practice

Not to be confused with

Related

How this term connects

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