Fonts have historically come in two flavors: PostScript, long favored by graphic designers, and TrueType, widely used in offices. Neither format was developed with electronic publishing in mind, and both impose substantial limitations on designers. Complex character sets are handled idiosyncratically (and differently by different manufacturers), multiple languages can be difficult or impossible to support, and neither format is implemented quite the same way on both Macs and PCs. Anyone who’s had to wonder where the alternate Q was in a font — only to find that it’s accessible on the Mac but not under Windows — is familiar with the eccentricities of PostScript and TrueType, now collectively called the “legacy” formats.
To answer these challenges, Adobe and Microsoft introduced the OpenType font format in 1997 as a successor to the legacy formats. Now entering its second decade, OpenType enjoys universal support across operating systems, wide support among applications, and — perhaps most importantly — the multilateral support of the software industry. In 2005, industry leader Adobe Systems shipped its last PostScript font, signalling a commitment to the exclusive development of OpenType. As of 2013, the entire library of Hoefler & Co. fonts is available exclusively in OpenType.
Key benefits of OpenType
100% cross-platform compatibility
Typographically complex documents have historically been difficult to exchange between the Mac and Windows, because each operating system renders certain arbitrary ranges of the character set inaccessible. (Ligatures added on a Macintosh will vanish under Windows; fractions added by a Windows user will disappear on the Mac.) OpenType fonts are designed to behave identically on both platforms, ensuring total compatibility among all electronic documents. And OpenType’s cross-platform support extends to operating systems that are obsolete by more than a decade, including Windows 95 and Mac OS 8.3.
Ease of management and implementation
In order to provide the best experience for users of either platform, type foundries manufacture Mac and Windows fonts in slightly different ways. Beyond the inconsistencies this can introduce to documents, these parallel font libraries can be cumbersome to manage. File names are inscrutable: the Macintosh file awkwardly named
MercuNumG1SemIta goes by
MERNM1DI.pfb under Windows (neither of which is recognizable as “Mercury Text Grade 1 Numeric Semibold Italic”), and frustratingly these separate software sources mean that designers who have licensed fonts for both platforms need to manage two separate versions of every font file. This can be especially daunting for large font families with a lot of “peripheral styles” (such as small caps, swashes, alternates, numerics, or tabular figures), since each of these peripheral styles will require its own set of font files. The PostScript version of Mercury Text Complete, for both platforms, has a dizzying 360 font files to manage.
OpenType fonts offer the revolutionary advantage of a single font file that can be installed on any computer for which the user has purchased a license, regardless of whether it’s a Mac or a PC. Since OpenType fonts allow peripheral styles to be gathered into a single font file — no more separate fonts for small caps, swashes, alternates, numerics, or tabular figures — OpenType families are also smaller: no longer 360 files, Mercury Text is just 24. Best of all, these files have understandable names: the OpenType version of Mercury Text Grade 1 Roman is called
Mercury Text Grade 1 Roman.otf.
Larger character sets
Legacy formats offer a mere 210 character positions that can be accessed reliably on both platforms, which has led type foundries to relegate peripheral styles to their own separate fonts. It’s also encouraged unorthodox policies about character positions: no two foundries store the non-standard ff ligature in quite the same place, which quickly becomes a nuisance when working with fonts from two different vendors. OpenType resolves this problem not only by allowing for a whopping 65,536 characters in a font, but by employing “Unicode encoding,” a methodology by which fonts can have an understanding of their own contents. Text that’s entered in a Unicode-encoded OpenType font always remains intact, despite whatever unique typographical niceties may be applied. An ff ligature is never option-Z, it’s always “ff,” allowing spell checks to continue to run even after the designer has cherried up the typography.
Extensive language support
OpenType’s ability to handle astronomically large character sets makes it possible to cover more languages than ever before. Where legacy fonts are produced in the “Latin-1” standard that covers only the major Western European languages, all OpenType fonts from Hoefler & Co. feature our own Latin-X™ character set, which additionally covers most of Africa, and all of Central and Eastern Europe — collectively reaching an additional 200,000,000 readers worldwide. This entire range of languages can be typeset from any keyboard, without the need for additional software or exotic keyboard drivers.
Support for advanced typographic features
Applications that are “OpenType-savvy” offer better ways of accessing all the rich features that we build into our fonts. Tasks that were once performed manually, like the insertion of ligatures or fractions, can now happen automatically. Many programs include an OpenType palette, which allows discretionary choices (like the use of proportional versus tabular figures) to be set globally. The potential of an OpenType font is limited only by the applications in which it’s used — an important difference between OpenType and legacy fonts, as you’ll see in the following section.
How OpenType differs
A new way of handling “peripheral styles”
Because of their limited character sets, a legacy font’s peripheral styles (such as small caps, swashes, alternates, numerics, or tabular figures) have historically been manufactured as separate fonts. OpenType fonts, owing to their almost boundless size, can incorporate all of these variants into a single font file. This approach has a number of benefits for designers: an entire document, even one containing many fonts, can be switched from old-style figures to lining figures in a single operation; a paragraph that features both small caps and upper- and lowercase text will preserve these qualities even when the font family is changed; a user can create a one-half fraction by simply typing “1/2”, instead of searching through the backwater of an “Alternate” or “Numeric” font to find the right glyph. All of these operations are possible with fonts that contain these features, provided that the application being used allows for the control of OpenType features.
While the reintegration of the type family offers enormous advantages for designers, it does represent a new way of working. Designers who have built documents with legacy fonts may encounter the one-time need to perform find-and-replace operations, in order to introduce OpenType fonts to their existing files. Those who are using outdated or unsophisticated software may find that the peripheral styles to which they’ve become accustomed are now irretrievably missing. This is because in OpenType, a font’s small caps (for example) are no longer provided as a separate font, but rather as an OpenType feature, and the extent to which applications support OpenType features varies, as you’ll see in the following section.
Varying application support for advanced features
Any program can use an OpenType font, but not every program offers the kind of advanced typographic controls needed to make the most of OpenType. A word processor such as WordPerfect, for example, can access all the characters in an OpenType font that are standard in a legacy font, but it can’t reach the distant Latin-X™ range. Microsoft Word can, so OpenType fonts can be used in Word to create documents in the full range of Latin-X™ languages, but Word offers no facility for activating peripheral styles such as small caps or swashes, or discretionary font features such as tabular figures or fractions. The following table indicates the degree to which OpenType fonts can be fully explored in a range of programs:
Latin-X™ character set
|Ligatures||Fractions & Scientific||Small Caps||Figure Styles
Old-style, lining, tabular, etc.
Alternate characters, etc.
|Adobe InDesign CS+||Yes||Yes||Yes||Yes||Yes||Yes|
|Adobe Illustrator CS+||Yes||Yes||Yes||Yes||Yes||—|
|Adobe Photoshop CS+||Yes||Yes||Yes||Yes||—||—|
|Quark XPress 7+||Yes||Yes||Yes||Yes||Yes||Yes|
|Microsoft Word 2010+||Yes||Yes||—||—||Yes||Yes|
|Microsoft Powerpoint 2010+||Yes||—||—||—||—||—|
|Microsoft Excel 2010+||Yes||—||—||—||—||—|
|Microsoft Office 2000+||Yes||—||—||—||—||—|
|Apple Pages ’09||Yes||Yes||—||—||Yes||Yes|
|Apple Keynote ’09||Yes||Yes||—||—||Yes||Yes|
|Apple Numbers ’09||Yes||—||—||—||—||—|
Most users will find these limitations unsurprising, since word processors and spreadsheets are not typographers’ tools (and most of these programs exhibit far more fundamental limitations, such as no kerning or no fractional point sizes.) However, those considering OpenType are encouraged to review the capabilities of the programs they most often use, as well as the font features most essential to the work they do.