What is AFM?

Adobe Font Metrics (AFM) is a text file describing Type 1 font metrics including character widths, kerning pairs, and bounding boxes.

What is OTF?

OTF (OpenType Font) is an extension of TrueType with support for advanced typographic features like ligatures, stylistic alternates, and swashes.

When Should You Use AFM vs OTF?

AFM vs OTF: Key Differences

• •AFM and OTF diverge on compression: lossless compression for the source, lossless compression for the target.
• •Since both AFM and OTF use lossless compression, the quality characteristics are comparable — differences in file size come down to how efficiently each format implements compression.
• •Alpha channel support: OTF lacks transparency support.
• •Storage footprint: Very small, text-based metrics for AFM vs 30KB to 300KB per font for OTF.
• •Use case fit: AFM targets postscript font metrics, pdf font embedding and OTF targets professional typography, advanced typesetting — your choice depends on which workflow stage you are serving.

Advantages of AFM

• ✓At its core, AFM relies on lossless encoding — a design choice that makes it perfect for PostScript font metrics, PDF font embedding.
• ✓You won't run into compatibility issues with AFM — it's a universal standard across platforms.
• ✓File size management with AFM: larger files guaranteed to match the original exactly.
• ✓Every major application in the PostScript font metrics, PDF font embedding space supports AFM natively.

Advantages of OTF

• ✓At its core, OTF relies on lossless encoding — a design choice that makes it perfect for Professional typography, advanced typesetting.
• ✓You won't run into compatibility issues with OTF — it's a universal standard across platforms.
• ✓File size management with OTF: larger files guaranteed to match the original exactly.
• ✓Every major application in the Professional typography, advanced typesetting space supports OTF natively.

Common Use Cases for AFM to OTF Conversion

• Desktop publishing
• E-book formatting
• User interfaces
• Marketing materials
• Packaging design
• Signage systems

Industry Applications

Best Practices for AFM to OTF Conversion

• →Before converting AFM to OTF, review the font license — some licenses restrict format conversion
• →Check hinting data after conversion: OTF may handle TrueType hinting differently than AFM
• →Verify that all character sets (Latin, Cyrillic, CJK, etc.) survived the conversion intact
• →Test the converted font in both a browser and a desktop application
• →Keep the original font file in case the conversion alters spacing metrics

Troubleshooting AFM to OTF Conversion

• !OTF font doesn't render correctly → check if OTF supports all glyphs present in AFM
• !Licensing restrictions after AFM to OTF conversion → verify the font license allows format conversion
• !Hinting data lost converting AFM to OTF → some font formats like OTF may not preserve TrueType hinting
• !Special characters missing from converted OTF → font subsetting may have removed unused glyphs

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