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 OTC?

OpenType Collection (OTC) bundles multiple OpenType fonts into one file, similar to TTC but for OpenType format.

When Should You Use AFM vs OTC?

AFM vs OTC: Key Differences

• •AFM uses lossless compression while OTC uses lossless compression — both take the same approach to file size management.
• •Since both AFM and OTC use lossless compression, the quality characteristics are comparable — differences in file size come down to how efficiently each format implements compression.
• •Transparency: N/A
• •File sizes: AFM files typically range Very small, text-based metrics and OTC files 5-30MB for font collections.
• •Use case fit: AFM targets postscript font metrics, pdf font embedding and OTC targets font distribution, font family packaging — your choice depends on which workflow stage you are serving.

Advantages of AFM

• ✓The lossless nature of AFM means file sizes stay reasonable while handling PostScript font metrics, PDF font embedding efficiently.
• ✓From mobile devices to enterprise servers, AFM is recognized and supported everywhere.
• ✓The trade-off for AFM's perfection is larger files — but for archival work, it is worth every megabyte.
• ✓AFM is a first-class citizen in all major software ecosystems, from creative suites to development environments.

Advantages of OTC

• ✓The lossless nature of OTC means file sizes stay reasonable while handling Font distribution, font family packaging efficiently.
• ✓From mobile devices to enterprise servers, OTC is recognized and supported everywhere.
• ✓The trade-off for OTC's perfection is larger files — but for archival work, it is worth every megabyte.
• ✓OTC is a first-class citizen in all major software ecosystems, from creative suites to development environments.

Common Use Cases for AFM to OTC Conversion

• Marketing materials
• Packaging design
• Signage systems
• Icon sets
• Logo design
• Data visualization

Industry Applications

Best Practices for AFM to OTC Conversion

• →Converting AFM to OTC: check that glyph coverage is preserved — some formats have character limitations
• →Use OTC for cross-platform compatibility
• →Test fonts across different browsers and operating systems after conversion
• →Always keep a backup of your original files before converting
• →Choose the appropriate quality settings for your specific use case

Troubleshooting AFM to OTC Conversion

• !The converted OTC font has incorrect metrics → advance width and kerning values may differ between formats despite identical glyphs
• !OTC file looks heavier or lighter than AFM → font rendering engines handle weight and anti-aliasing differently per format
• !OpenType features (ligatures, swashes) lost after conversion to OTC → verify the target format supports advanced typographic features
• !Variable font axes missing from the converted OTC → variable font support varies significantly between formats

Related Font Converters

All Font Formats

More Font tools