Type 1 to Modern Formats

Adobe Type 1 fonts (PFB/PFA) are legacy PostScript fonts. Fontisan provides comprehensive support for converting them to modern formats.

Overview

Type 1 fonts use:

• Cubic Bézier curves — Compatible with CFF/OpenType
• PostScript hints — Different from TrueType instructions
• Custom encoding — May lack Unicode mappings

Type 1 → OTF

Convert Type 1 fonts to OpenType/CFF format.

Recommended Options

Fontisan::ConversionOptions.recommended(from: :type1, to: :otf)
# Returns:
# opening: { decompose_composites: false, generate_unicode: true }
# generating: { hinting_mode: "none", decompose_on_output: true }

CLI

# Basic conversion
fontisan convert font.pfb --to otf --output font.otf

# With preset
fontisan convert font.pfb --to otf --preset type1_to_modern --output font.otf

# With Unicode generation
fontisan convert font.pfb --to otf --generate-unicode --output font.otf

Key Considerations

• Unicode: Generated from Adobe Glyph List
• CharStrings: Type 1 → CFF format (direct conversion)
• Hinting: PostScript hints preserved in CFF
• seac composites: Must be expanded (CFF doesn't support seac)

Type 1 → TTF

Convert Type 1 fonts to TrueType format.

Recommended Options

Fontisan::ConversionOptions.recommended(from: :type1, to: :ttf)
# Returns:
# opening: { decompose_composites: false, generate_unicode: true }
# generating: { hinting_mode: "full" }

Workflow

Type 1 → CFF (OTF) → TTF

Key Considerations

• Two-step conversion compounds approximation errors
• Curve conversion: CFF cubic → TrueType quadratic
• Unicode: Generated from glyph names

CLI

fontisan convert font.pfb --to ttf --autohint --output font.ttf

OTF → Type 1

Convert OpenType fonts back to Type 1 for legacy systems.

Recommended Options

Fontisan::ConversionOptions.recommended(from: :otf, to: :type1)
# opening: { decompose_composites: false }
# generating: { write_pfm: true, write_afm: true, write_inf: true,
#              select_encoding_automatically: true, hinting_mode: "preserve",
#              decompose_on_output: false }

CLI

fontisan convert font.otf --to type1 --output font.pfb

Limitations

• Reverse conversion from CFF to Type 1
• Modern OpenType features (GPOS, GSUB variations) lost in Type 1
• CFF hints may not translate exactly to Type 1 hints

Type 1 → Type 1 (Copy)

Re-encode Type 1 font or regenerate metrics files.

Recommended Options

Fontisan::ConversionOptions.recommended(from: :type1, to: :type1)
# opening: { decompose_composites: false, generate_unicode: true }
# generating: { write_pfm: true, write_afm: true, write_inf: true,
#              select_encoding_automatically: true, hinting_mode: "preserve" }

CLI

# Regenerate metrics files
fontisan convert font.pfb --to type1 --write-pfm --write-afm --output font-copy.pfb

seac Composite Handling

Type 1 fonts use seac (Standard Encoding Accented Character) for composite glyphs. CFF doesn't support seac, so these must be expanded.

# seac composites are automatically decomposed
options = Fontisan::ConversionOptions.new(
  opening: { decompose_composites: true }
)

What seac Does

# seac combines two glyphs:
# Example: é = e + ´ (acute accent)
#
# In Type 1:
# /eacute { seac (e) (acute) } def
#
# In CFF/OTF:
# Must be expanded to actual outlines

Presets

type1_to_modern

Optimize Type 1 fonts for modern use:

Fontisan::ConversionOptions.from_preset(:type1_to_modern)
# From: :type1, To: :otf
# opening: { generate_unicode: true, decompose_composites: false }
# generating: { hinting_mode: "preserve", decompose_on_output: true }

Use cases:

• Modernizing legacy Type 1 fonts
• Preparing fonts for web use
• Converting fonts for modern applications

modern_to_type1

Convert modern fonts back to Type 1:

Fontisan::ConversionOptions.from_preset(:modern_to_type1)
# From: :otf, To: :type1
# opening: { convert_curves: true, scale_to_1000: true,
#           autohint: true, decompose_composites: false,
#           store_custom_tables: false }
# generating: { write_pfm: true, write_afm: true, write_inf: true,
#              select_encoding_automatically: true,
#              hinting_mode: "preserve" }

Use cases:

• Legacy system compatibility
• Font distribution for older applications
• Working with Type 1 workflows

Examples

Convert Type 1 to Web Font

# Direct to WOFF2
fontisan convert font.pfb --to woff2 --output font.woff2 --preset type1_to_modern

# With custom options
fontisan convert font.pfb --to woff2 --output font.woff2 \
  --generate-unicode --optimize-tables

Batch Convert Directory

Dir.glob('legacy/*.pfb').each do |input|
  output = input.sub('.pfb', '.otf').sub('legacy/', 'modern/')
  Fontisan.convert(input, output_format: :otf, output_path: output)
end