OTF vs PFB: Complete Format Comparison
Comprehensive comparison of OpenType Font (OTF) and PostScript Font Binary (PFB) covering technical foundations, curve mathematics, compatibility, and migration from legacy PostScript to modern OpenType
In Simple Terms
PFB (PostScript Type 1) is deprecated legacy format from 1984. Adobe ended support in January 2023. OTF is the modern replacement.Convert all PFB fonts to OTF immediately for continued use. OTF contains same PostScript curves in modern container with better features.Use OTF for desktop work. Convert OTF to WOFF2 for web. PFB has no place in modern workflows—migrate now before compatibility breaks.
In this article
OpenType Font (OTF) and PostScript Font Binary (PFB) represent two generations of professional font technology, with OTF being the modern unified standard and PFB being the legacy PostScript Type 1 format that dominated professional publishing from 1984 to the early 2000s. OTF, jointly developed by Adobe and Microsoft in 1996, is a comprehensive font format that can contain either TrueType outlines (quadratic Bézier curves) or PostScript/CFF outlines (cubic Bézier curves), supporting advanced typographic features and cross-platform compatibility. PFB, created by Adobe as part of the PostScript specification in 1984, stores PostScript Type 1 font data as binary-encoded cubic Bézier curves, historically used as two files: PFB (outline data) and PFM/AFM (metrics).
The critical distinction is that OTF succeeded and replaced PFB as the professional standard. OTF files with PostScript outlines (.otf extension) contain the same cubic Bézier curve technology as PFB but in a modern, standardized container with better features and universal support. PFB files (40-120 KB) were designed for PostScript printers and professional typesetting, while OTF files (150-300 KB) work across all platforms and output devices. Modern operating systems and applications still support PFB for backward compatibility, but Adobe and all major foundries now distribute fonts as OpenType (OTF/TTF) rather than the old PostScript Type 1 (PFB) format. The font industry completed its transition from PFB to OTF in the mid-2000s.
This comprehensive guide compares OTF and PFB to clarify their relationship and explain why OTF replaced PFB. You'll learn the technical specifications of both formats, how OTF unified TrueType and PostScript technologies, curve mathematics showing OTF can contain PostScript data, platform compatibility demonstrating OTF's superiority, conversion methods from PFB to OTF preserving cubic curves, and migration strategies for replacing legacy PFB fonts. Whether maintaining legacy documents or understanding professional font history, this guide provides essential knowledge about these formats' evolution from PostScript dominance to OpenType universality.
Format Overview
OpenType Font (OTF)
History and Purpose:
- • Developed by Adobe and Microsoft (1996)
- • Unified TrueType and PostScript Type 1 technologies
- • Designed to replace both TTF and PFB formats
- • Became industry standard by mid-2000s
- • Actively maintained and evolved (2025)
Technical Characteristics:
- • Can contain TrueType outlines (quadratic Bézier)
- • Or PostScript/CFF outlines (cubic Bézier, like PFB)
- • Advanced OpenType features (GSUB, GPOS tables)
- • Single unified file format
- • Extensions: .otf (PostScript) or .ttf (TrueType)
Current Status (2025):
- • Universal professional standard
- • All major foundries distribute as OTF
- • File size: 150-300 KB (Latin fonts)
- • Recommended for all projects
PostScript Font Binary (PFB)
History and Purpose:
- • Created by Adobe (1984) as part of PostScript
- • Dominated professional publishing 1984-2005
- • Designed for PostScript printers and typesetters
- • Mathematical elegance with cubic Bézier curves
- • Replaced by OpenType format
Technical Characteristics:
- • PostScript Type 1 format
- • Cubic Bézier curves (3 control points)
- • Binary-encoded PostScript commands
- • Two-file system: PFB (outlines) + PFM/AFM (metrics)
- • Extension: .pfb (binary) or .pfa (ASCII)
Current Status (2025):
- • Legacy format, no longer distributed by foundries
- • Limited modern OS support
- • File size: 40-120 KB (outline data only)
- • Convert to OTF for modern use
Key Relationship: OTF Unified PostScript and TrueType
OpenType resolved the TrueType vs PostScript format wars:
- 1980s-1990s: PostScript (PFB) vs TrueType (TTF) rivalry
- 1996: Adobe + Microsoft create OpenType to unify formats
- OTF with CFF: Contains PostScript curves, same as PFB
- Result: OTF can contain either TrueType or PostScript data
- Modern: PFB data converted to OTF (CFF) format
Technical Differences
Comprehensive Technical Comparison
| Feature | OTF (CFF) | PFB |
|---|---|---|
| Curve Type | Cubic Bézier (same as PFB) | Cubic Bézier |
| Developer | Adobe + Microsoft | Adobe only |
| Year Created | 1996 | 1984 |
| File Structure | Single unified file | Two files (PFB + PFM/AFM) |
| OpenType Features | Full support | Limited/none |
| Platform Support | Universal | Limited modern support |
| File Size | 150-300 KB | 40-120 KB (outlines only) |
| Modern Use | Current standard | Legacy only |
| Foundry Distribution | Yes (standard) | No (discontinued) |
Cubic Bézier Curves: Same Technology
Both OTF (with CFF) and PFB use identical cubic Bézier mathematics:
- • Formula: B(t) = (1-t)³P₀ + 3(1-t)²tP₁ + 3(1-t)t²P₂ + t³P₃
- • Two endpoints + two control points
- • Mathematically elegant for complex curves
- • Same precision and quality
- • Standard in professional design tools
Key insight: OTF (CFF) contains the same PostScript curve technology as PFB, just in a modern container.
OTF's Dual Nature: TrueType or PostScript
OpenType is a wrapper that can contain either outline type:
- OTF with TrueType outlines (.ttf): Quadratic Bézier curves
- OTF with PostScript/CFF outlines (.otf): Cubic Bézier curves (same as PFB)
- Both get: Advanced OpenType features (GSUB, GPOS, ligatures, alternates)
- Result: Unified format supporting both technologies
Two-File System vs Single File
PFB Two-File System:
- • PFB file: Binary outline data (curves, hints)
- • PFM file (Windows) or AFM file (Mac/Unix): Metrics
- • Both required for proper function
- • Installation complexity and file management issues
OTF Single File:
- • All data in one .otf file
- • Outlines, metrics, features, metadata
- • Simple installation: drop one file
- • Easier file management
Quality and Rendering
Print Quality: Identical
OTF (CFF) and PFB produce identical print output:
- • Same curves: Both use cubic Bézier mathematics
- • Same precision: Identical mathematical definitions
- • Same PostScript output: RIP processes identically
- • Professional quality: Both suitable for high-end printing
The 1990s perception that PostScript (PFB) had better print quality was about workflow integration, not mathematical superiority.
Screen Rendering
- Historical (1990s): PFB had basic PostScript hinting, required Adobe Type Manager (ATM) for good screen rendering
- OTF advantage: Can include either PostScript or TrueType hinting (TrueType hinting is more sophisticated)
- Modern reality: High-DPI displays (Retina, 4K) make hinting less critical
- Result: OTF (CFF) renders excellently on modern screens
Why OTF Replaced PFB
- Unified format: One format supporting both TrueType and PostScript
- Better features: Advanced OpenType features PFB couldn't support
- Simpler workflow: Single file vs PFB+PFM two-file system
- Cross-platform: Works identically on Windows, Mac, Linux
- Industry consensus: Adobe and Microsoft agreed on one standard
- Forward compatibility: Designed for future expansion
Platform Compatibility
Operating System Support
| Platform | OTF | PFB | Notes |
|---|---|---|---|
| Windows 11/10 | ✓ | ~ | Limited PFB support |
| Windows 7/XP | ✓ | ✓ | With ATM Light |
| macOS (Modern) | ✓ | ~ | Deprecated, prefers OTF |
| Linux | ✓ | ~ | Depends on config |
| iOS/Android | ✓ | ✗ | No PostScript Type 1 |
PFB Modern Limitations
- Windows: No native support; required ATM (discontinued 2013)
- macOS: Deprecated PostScript Type 1 fonts in favor of OTF
- Adobe CC: Still supports PFB but strongly recommends converting to OTF
- Mobile: No PFB support on iOS or Android
- Web: Cannot use PFB; must convert to OTF then WOFF2
- Future: PFB support declining, OTF is the standard
OTF Universal Support
- • All operating systems: Native support on Windows, macOS, Linux
- • All design tools: Photoshop, Illustrator, InDesign, Figma, Sketch
- • All office suites: Microsoft Office, Google Docs, LibreOffice
- • Mobile platforms: iOS, iPadOS, Android
- • Web deployment: Convert to WOFF2 for websites
- • Print production: RIPs process OTF natively
Conversion Methods
Converting PFB to OTF
Method 1: FontForge (Preserves PostScript Curves)
- Install FontForge (free, open source)
- File → Open → Select PFB file (auto-finds PFM if present)
- File → Generate Fonts
- Select "OpenType (CFF)" format
- This preserves cubic Bézier curves
- Save as .otf
Important: Use "OpenType (CFF)" not "OpenType (TrueType)" to preserve PostScript curves.
Method 2: Adobe Font Development Kit (AFDKO)
# Install AFDKO pip install afdko # Convert PFB to OTF (CFF) makeotf -f font.pfa -o font.otf
Method 3: Online Converter
- Visit font-converters.com
- Upload PFB file
- Select OTF (CFF) as output
- Download converted file
Conversion Considerations
- Preserve curves: Convert to OTF (CFF) to keep cubic Bézier curves
- Lossless conversion: PostScript data transferred exactly
- Single file: OTF combines outline and metric data
- File size increase: OTF may be 2-3× larger due to additional tables
- Quality maintained: No visual difference in output
- Features preserved: Basic kerning and encoding maintained
Don't Convert to TrueType
If converting PFB, convert to OTF (CFF), not TTF:
- • OTF (CFF): Preserves cubic Bézier curves exactly
- • TTF conversion: Converts cubic to quadratic, adds control points
- • File size: TTF may be 20-40% larger after conversion
- • Best practice: Keep PostScript as PostScript (OTF/CFF)
Modern Recommendations
Use OTF For All Projects:
- • New work: All foundries distribute fonts as OTF
- • Professional typography: OTF is the industry standard
- • Cross-platform: Works on all operating systems
- • Advanced features: Ligatures, alternates, contextual forms
- • Web deployment: Convert OTF to WOFF2 for websites
When You Encounter PFB:
- • Legacy documents: InDesign/QuarkXPress files from 1990s-2000s
- • Old font libraries: Professional collections pre-OpenType
- • Archive projects: Historical materials requiring exact fonts
Action: Convert PFB to OTF (CFF) for modern compatibility
Migration Workflow
- Identify PFB fonts: Search font libraries and project folders
- Check licensing: Verify conversion rights
- Convert to OTF (CFF): Preserve PostScript curves
- Test converted fonts: Compare rendering in applications
- Update projects: Replace PFB references with OTF
- Archive originals: Keep PFB as backup
Best Practices Checklist
- ☐ Convert legacy PFB fonts to OTF (CFF)
- ☐ Use OTF for all new font purchases
- ☐ Avoid converting PostScript to TrueType
- ☐ Test converted fonts in target applications
- ☐ Maintain font source files (OTF) separately
- ☐ Convert OTF to WOFF2 for web deployment
- ☐ Document font sources and licenses
- ☐ Archive original PFB files for legacy projects
Summary: OTF vs PFB
OTF and PFB represent the evolution from PostScript Type 1 to OpenType. Both can use cubic Bézier curves—OTF (with CFF outlines) contains the same PostScript curve technology as PFB, just in a modern, unified container. PFB dominated professional publishing from 1984-2005 but required two files (PFB + PFM/AFM) and had limited modern platform support. OTF unified TrueType and PostScript technologies, providing advanced features, single-file simplicity, and universal compatibility.
Always use OTF for modern projects—all foundries now distribute fonts as OpenType. Convert legacy PFB fonts to OTF (CFF) using FontForge or AFDKO to preserve cubic Bézier curves. OTF replaced PFB as the professional standard by the mid-2000s due to better features, simpler workflow, and cross-platform support. PFB is now legacy technology maintained only for backward compatibility with old documents. OpenType's unification of TrueType and PostScript ended the format wars, with OTF becoming the universal standard.
Written & Verified by
Sarah Mitchell
Product Designer, Font Specialist
OTF vs PFB FAQs
Common questions answered about this font format comparison