What is PFB? The PostScript Type 1 Binary Font Format Explained
Adobe's binary container for PostScript Type 1 outline fonts.
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What is PFB?
PFB, short for Printer Font Binary, is a binary file format created by Adobe Systems for storing PostScript Type 1 outline fonts. Type 1 fonts were introduced by Adobe as part of the PostScript page description language and came into wide use with the Apple LaserWriter in 1985.
A PFB file is a compact wrapper around the data that would otherwise appear in an ASCII PFA file. It is organized as a series of segments, each marked as ASCII text or binary, where the binary portions, including the encrypted charstring outlines, are stored as raw bytes rather than as hexadecimal text. This makes PFB files roughly half the size of equivalent PFA files. On Windows, a PFB is paired with a PFM metrics file.
How PFB Works
A PFB file packages a PostScript Type 1 font as a series of segments, each tagged by a binary marker that identifies the following data as ASCII text or raw binary.[3] The clear-text segment holds the font dictionary and encoding, while the binary segments contain the eexec-encrypted charstrings that define each glyph's outline as cubic Bezier curves with hinting.[1]
PFB vs PFA and Metrics
PFB is the binary counterpart of the PFA format, which encodes the same binary sections as hexadecimal text; storing them as raw bytes roughly halves file size.[3] On Windows a PFB is paired with a PFM file that supplies font metrics such as character widths and kerning.[3]
History and End of Support
Type 1 fonts debuted with PostScript and the Apple LaserWriter in 1985 and dominated professional publishing for years.[1] Adobe has since ended support for Type 1 in its applications, encouraging migration to OpenType, so PFB is now considered a legacy format.[2]
MKV Technical Specifications
PFB vs Other Font Formats
| Feature | PFB | TTF | OTF |
|---|---|---|---|
| Outline type | PostScript Type 1[1] | TrueType (quadratic) | PostScript / TrueType |
| Standardized by | Adobe[1] | Apple / ISO | Microsoft / Adobe / ISO |
| Web-optimized | No[3] | Partial | Partial |
| Current support | Deprecated[2] | Active | Active |
| Best for | Legacy print workflows | General use | Advanced typography |
PFB holds legacy Type 1 outlines that modern apps have largely retired in favor of TTF and OTF.
Advantages & Disadvantages
Advantages
Storing the binary section as raw bytes makes a PFB about half the size of the equivalent ASCII PFA file.
Type 1 fonts use cubic Bezier curves and hinting for crisp rendering, especially in print.
As the foundation of professional PostScript printing, Type 1 fonts were a print and publishing standard for decades.
Long supported across major operating systems and PostScript devices.
Disadvantages
Adobe ended authoring and support for Type 1 fonts in its applications in January 2023, encouraging migration to OpenType.
Type 1 fonts typically hold far fewer glyphs than modern OpenType fonts and lack advanced typographic features.
On some platforms a font requires separate outline and metrics files, complicating management.
Common Use Cases
PFB is encountered mainly in legacy print and font-archival contexts.
Legacy print workflows | FileFormer
Older professional publishing and prepress systems relied on PostScript Type 1 fonts in PFB form.
Font conversion | FileFormer
PFB files are converted to OpenType or other modern formats to keep older typefaces usable.
Digital preservation | FileFormer
Archives retain PFB fonts to reproduce historical documents and designs accurately.
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Try Font Converter FreeFrequently Asked Questions
What is the difference between PFB and PFA?
Both store PostScript Type 1 fonts, but PFB keeps the binary section as raw bytes while PFA encodes it as hexadecimal text, making PFB files about half the size.
What is a PFM file?
PFM (Printer Font Metrics) is the companion file on Windows that holds font metric data, used alongside the PFB outline file.
Are PostScript Type 1 fonts still supported?
Adobe ended support for authoring with Type 1 fonts in its applications in January 2023 and recommends OpenType instead.
Can I convert a PFB font to OpenType?
Yes. Font tools can convert PostScript Type 1 PFB fonts into OpenType or TrueType formats for modern use.
Who created the PFB format?
Adobe Systems created PFB as part of its PostScript Type 1 font technology.