Font Technical Deep Dive
Comprehensive technical guides for understanding font internals. Master OpenType tables, hinting mechanisms, glyph representations, validation tools, and compression algorithms used in modern font formats.
Why Technical Understanding Matters
Font conversion isn't just changing file extensions—it involves complex transformations of outline data, hinting instructions, kerning tables, and metadata. Understanding what happens inside font files helps you make informed decisions about format selection, anticipate quality trade-offs, and troubleshoot rendering issues. These guides bridge the gap between "it works" and "I know why it works."
Font Hinting Preservation
How TrueType and CFF hinting instructions survive format conversion
Kerning Tables
Understanding KERN and GPOS tables for precise letter spacing
OpenType Features Support
Which GSUB and GPOS features transfer during font conversion
Font Embedding Bits
Understanding fsType permissions and licensing restrictions
Unicode Ranges
Character set preservation and cmap table handling
Font Metrics
Line height, x-height, ascender and descender preservation
Glyph Outlines
TrueType quadratic vs CFF cubic Bezier curve quality
Font Validation
Testing converted fonts with Font Bakery and OpenType Sanitizer
Font File Anatomy
Understanding font table structure and organization
Compression Algorithms
WOFF zlib vs WOFF2 Brotli compression comparison
Quick Technical Reference
Required OpenType Tables
- • cmap - Character to glyph mapping
- • head - Font header information
- • hhea - Horizontal header metrics
- • hmtx - Horizontal metrics data
- • maxp - Maximum profile stats
- • name - Naming table (metadata)
- • OS/2 - Windows-specific metrics
- • post - PostScript information
Outline Formats
- • TrueType: Quadratic Bezier curves
- • CFF/PostScript: Cubic Bezier curves
- • TTF uses glyf + loca tables
- • OTF uses CFF or CFF2 table
- • Cubic → Quadratic adds points
- • Quadratic → Cubic is exact
Compression Comparison
- • WOFF: zlib (DEFLATE) compression
- • WOFF2: Brotli + preprocessing
- • WOFF: ~40-50% smaller than TTF
- • WOFF2: ~20-30% smaller than WOFF
- • WOFF2: 97%+ browser support
- • Always prefer WOFF2 for web
Ready to Convert with Confidence?
Now that you understand what happens inside font files, put that knowledge to work with our conversion tools.