T11 to PPM Converter

T11 (Type 11) is a PostScript font type defined by Adobe Systems as part of the CID-keyed font architecture, combining CID glyph addressing with TrueType outline data wrapped in a Type 42 PostScript shell. In Adobe's font type numbering, Types 9, 10, and 11 are CID-keyed counterparts to Types 1, 3, and 42 respectively — so Type 11 is essentially a CID-keyed Type 42, designed for TrueType fonts that contain very large glyph sets, particularly CJK (Chinese, Japanese, Korean) character collections. The format allows PostScript interpreters with TrueType rasterizer support to render CJK TrueType fonts while using CID numeric indexing instead of glyph names, which is critical for character sets numbering in the tens of thousands. Glyph outlines remain in native TrueType quadratic spline format, preserving the original hinting instructions, while the CID layer provides efficient glyph access and subsetting through CMap resources. One advantage is direct TrueType rendering quality — unlike converting TrueType outlines to PostScript cubics, Type 11 passes the original outlines to the rasterizer intact, preserving hand-tuned grid-fitting instructions. The CID indexing provides another benefit by supporting multiple encoding schemes (Unicode, national standards) mapped to the same glyph collection without data duplication. Type 11 fonts appear primarily in professional CJK print production and PDF document workflows where large TrueType-based character sets must be embedded in PostScript-derived output.