Font Formats

Table of Contents

• Font Formats
  • Table of Formats
  • Source Font Formats
    • FontLab format (VFC)
    • FontLab JSON format (VFJ)
  • Final Font Formats
    • OpenType TT (TTF)
    • OpenType CFF (OTF)
    • Color Font Formats
    • Web Open Font Format (WOFF and WOFF2)
    • EOT
    • PostScript Type 1
    • OpenType SVG
  • Interchange font formats
    • FontLab Studio 5 (VFB)
    • Unified Font Object (UFO)
    • Extended Font Object (XFO)
    • PhotoFont (PHF)
    • Fontographer (FOG)
    • Glyphs (.glyphs)
  • Working with font files

Table of Formats

Font Format	Import	Export	Comments
OpenType TT (TTF)	+	+
OpenType CFF (OTF)	+	+
FontLab binary format (VFC)	+	+
FontLab JSON format (VFJ)	+	+
Glyphs fonts (.GLYPHS)	+
Unified Font Object (UFO)	+	+	v2 is supported now
Compressed UFO (UFOZ)	+	+
Extended Font Object (XFO)	+	+
FontLab Studio 5 (VFB)	+	+
Mac PostScript Type 1 (suitcases)	+
Win PostScript Type 1 (PFB)	+	+
Photofont (PHF)	+
Embedded OpenType (EOT)	+	+
OpenType SVG fonts (SVG)	+	+
Web fonts (WOFF & WOFF2)	+	+

Source Font Formats

FontLab offers two native file formats for saving: VFC (binary) and VFJ (JSON based). Both can keep all elements used in the font design process. Saving in any other format is actually an export and is likely to lose some elements such as glyph notes, pins, element references, etc. VFC is faster, but VFJ is human-readable.

FontLab format (VFC)

The VFC file format is only used in FontLab (and potentially by future FontLab apps). It is an extension to the FontLab Studio VFB format. You cannot install VFC files in Windows or macOS, but this format can retain all your font production elements. VFC for FontLab is like PSD for Adobe Photoshop. It is binary and optimized for fast reading and writing by the computer, to make working with it very quick.

The format is cross-platform-compatible so VFC files saved from the Windows version can be opened in the Mac version and vice versa. In addition, the format is designed with the potential to be largely upward (future) compatible.

FontLab JSON format (VFJ)

This is a JSON-format FontLab native file. Where VFC is binary and optimized for speed, VFJ is a text-based representation that is both human-readable, and also potentially good for interchange with, or analysis by, other apps.

Final Font Formats

The following list shows the font formats FontLab can export, with some considerations for their usage and advantages/disadvantages.

Final Font Formats are those that can be installed or used directly in operating systems and browsers. Some data that is useful in development may be lost or simplified in final formats.

OpenType TT (TTF)

Also known as: TrueType, Windows TrueType, TrueType-flavored OpenType, TTF

Pros: Works on Windows, Linux and Mac OS X. May contain up to 65,535 glyphs, supports Unicode and can contain OpenType Layout features.

Suitable for Western Roman fonts, non-Latin fonts, multilingual fonts and advanced typography. May include class kerning allowing for smaller kerning tables. TrueType hinting allows better/stronger control of rendering at small sizes on screen. Can also contain bitmaps, although few operating systems will use them. Can include embedding permissions information defining whether or not the font may be included inside electronic documents (such as PDF and ebooks). Preferred by web developers.

Cons: Does not work on Classic Mac OS (8/9). May cause output problems on earliest PostScript (1993 and earlier) output and printing devices. Designers usually start by converting the outlines from cubic Bézier curves to TrueType, which may introduce very slight changes in the shape. When converted back to Bézier curves (e.g. by drawing programs), the resulting curves often have superfluous points. Manual TrueType hinting is powerful, but labor-intensive. The advanced typography features only work with new OpenType-savvy applications. For font families, requires two versions of the name information within each font: a typographic family first may contain any number of styles; the second “brief family” used on older Windows applications may contain only four styles.

OpenType CFF (OTF)

Also known as: OpenType-PS, PostScript-flavored OpenType, OTF

Pros: Works on Windows, Linux, Mac OS X. Uses the same cubic Bézier curves as PostScript Type 1, which are largely preferred by designers and in drawing apps, so letterforms can be drawn precisely and outlines need not be converted. May contain up to 65,535 glyphs, supports Unicode and can contain OpenType Layout features.

Suitable for Western Roman fonts, non-Latin fonts, multilingual fonts and advanced typography. May include class kerning allowing for moderately-sized kerning tables. Uses Type 1 hinting that is relatively easy to create. Can include embedding rights information defining whether or not the font may be attached to electronic documents.

Cons: Type 1 hinting does not allow precise control in small screen sizes. Can theoretically contain bitmaps, but they are not displayed. Not all multilingual and advanced typography features work in all applications. As with OpenType TT, two alternative family naming schemes within each font must be devised: one where a family contains an arbitrary number of styles, and second “brief family” where one family does not contain more than four styles.

Color Font Formats

Modern OpenType font formats support color outlines and/or bitmaps in glyphs. Different color formats have different capabilities and are supported in different places. Please see the Color Font Formats article for details.

Web Open Font Format (WOFF and WOFF2)

Web Open Font Format (WOFF) is actually an OpenType or TrueType font with compression and some additional data for use on web pages. Its purpose is to support font distribution from a web server to a client browser over a network.

WOFF 2.0 (WOFF2), with reference code provided by Google, is an update with improved compression. WOFF 2.0 uses Brotli as the byte-level compression format, giving more than 30% reduction in file size.

EOT

The so-called Embedded OpenType (EOT) format was invented by Microsoft as a very early Web font format in the 1990s. Today, EOT files are mostly useful as Web fonts for older versions of Internet Explorer, which understand EOT but are not compatible with any other web font format.

Like other web font formats, EOT functions primarily as a way of packaging an existing font format, in this case usually TrueType (TTF). EOT packaging was originally a secret/proprietary encrypted format and included the ability to lock a file to only be viewable/useable on the web site it was intended for, but in trying to make it a generally useable web font format, Microsoft published the specification.

PostScript Type 1

Also known as: Windows PostScript, PC PostScript, PC Type 1
File extension: .pfb + .pfm, with supplementary files .afm, .inf

NOTE: FontLab does not support:

• saving Mac suitcase-based Type 1 fonts (but can open them)
• Type 1 Multiple Master fonts (opening or saving, whether Mac or Windows)
• FontLab can, however, open a VFB or UFO representation of multiple master data

Pros: Works on Windows and Linux. Works on all PostScript output and printing devices. Uses the same curve system (cubic Bézier) as drawing applications such as Illustrator and Freehand, so letterforms are easy to edit when converted to curves. Type 1 hinting is comparatively easy to create and edit.

Cons: Does not work on Mac OS (it has its own distinct Mac-only flavor of Type 1), not cross-platform. Contains two parts, the outline file (.pfb) and the metrics font (.pfm), both of which must be in the same folder. Does not contain class kerning so kerning tables are large. Type 1 hinting does not allow precise control for very small screen sizes. Cannot include more than 256 encoded characters and lacks advanced layout features such as ligatures, making the format unsuitable for multilingual or non-Latin fonts. One family cannot contain more than four styles.

OpenType SVG

OpenType SVG fonts are OpenType fonts that have glyph data in SVG format. This newer OpenType format variation allows for the inclusion of colors, gradients, and color bitmaps. OpenType SVG is supported in some recent apps, including Adobe Photoshop 2017, Mozilla Firefox, and also in the Microsoft Edge browser on Windows 10. These. Its primary purpose has been as a way of supporting color in a font.

NOTE: An “SVG font” (non OpenType) is a different format, an older way of wrapping SVG format graphics with minimal structure to work like a font. Support for SVG fonts has been increasingly removed from modern standards and browsers. FontLab does not export SVG fonts; they are mentioned here simply to clarify that they are a different thing from OpenType SVG fonts.

Interchange font formats

Storage/interchange formats are those that are used by font editing apps, either as a main file format or for exchange with other font editors.

FontLab Studio 5 (VFB)

The .vfb file format is the proprietary format in FontLab Studio 5. It is fully backwards-compatible, so FontLab can open any .vfb file created in FontLab 3.x and 4.x, or in FontLab Studio 5. The format is also cross-platform-compatible so .vfb files saved from the Windows version can be opened in the version for Mac OS X and vice versa. In addition, the format is largely upward-compatible. This means that a .vfb file exported by FontLab can be opened in FontLab 3.x, 4.x or 5.x, as well as other FontLab Ltd. products such as TransType or TypeTool.

FontLab imports and exports .vfb. However, it does not convert Variations back to FontLab Studio Multiple Master data. As MM imported into is upgraded into the Variations format, this means that MM cannot be easily round-tripped from 5 to and then back to 5.

Unified Font Object (UFO)

UFO is an XML-based interchange format, and is the native format of some font tools.

FontLab can import UFO, and save as UFO. However, as UFO can not represent all features and concepts used in FontLab, some kinds of advanced data will be lost or converted when saving UFO, such as smart corners, nodes being genius or servant nodes, etc.

Extended Font Object (XFO)

XFO is an extended version of UFO created as a lossless representation of FontLab native data. It has an XML-based structure like UFO, but it adds representation of all FontLab data, so nothing is lost when saving to XFO. Third party applications and utilities wanting to interoperate well with FontLab are encouraged to consider using XFO as their interchange format.

PhotoFont (PHF)

PhotoFont format is Fontlab BitFonter’s font format for saving color bitmap fonts. The PhF font contains glyphs as a set of true color bitmap images. The PhF font may consist of one or several files: the main XML-based text file (which may also contain bitmap image data) and the bitmap image (or images) files containing actual glyph shapes referenced from the main file. I.e. the bitmap image data can be placed either in the main file or in separate files referenced by the main file.

PhotoFont format is now supported by BitFonter 3, TransType 4, Fontlab Pad and FontLab. It is not supported by any OS so PHF fonts cannot be installed directly. FontLab can import fonts in PhotoFont format.

Fontographer (FOG)

Fontographer format is the proprietary format in Fontographer. FontLab can import fonts in FOG 4 and 5 format.

Glyphs (.glyphs)

Glyphs format is the proprietary format of Glyphs 2. FontLab can import fonts in Glyphs format.

Working with font files

To start working on a new font, use the File > New Font (CmdN) command. See the Creating a New Font section for details.

To open or import existing fonts in the source, final or interchange format, use the File > Open Fonts (CmdO) command. You can open several fonts at once. See the Opening an Existing Font section for details.

To save your work in the source font formats (VFC and/or VFJ), use the File > Save (CmdS) or File > Save As (CmdShiftS) command. You can save several fonts at once if you select them in the Fonts panel. See the Saving a Font section for details.

To export fonts in the final font formats (OTF, TTF, WOFF, EOT, etc) or in the interchange format (VFB, UFO), use the File > Export Fonts (CmdE) command or File > Export Fonts As submenu. You can export several fonts at once if you select them in the Fonts panel. See the Exporting Fonts section for details.