fonts are a font format developed by Adobe, used primarily in PostScript and PDF files for large character sets (e.g., Chinese, Japanese, Korean). Unlike traditional fonts, CID fonts separate character shape (glyph) from encoding, making them efficient for CJK typography.

The F series, comprising F1, F2, and F3, refers to a subset of CID Fonts optimized for specific use cases. These fonts are designed to provide a consistent visual aesthetic while catering to diverse typographic requirements.

| Error Message | Solution | | :--- | :--- | | F1 not found, using Courier | The PDF is calling a specific CID version (e.g., CIDFont+F1 ). Use Acrobat Pro to embed the font subset. | | F2 missing / Illegal font format | Your printer requires the , not OpenType. Convert .otf to .pfb using TTX/FontForge . | | F3 download failed (Timeout) | The rasterizer’s memory is full. Clear the font cache via the service mode (Canon: Level 2 > #CLEAR FONT). | | Font shows but prints garbled | You have a byte-order conflict. Redownload the "Eastern Asia" specific pack, not the Western version. |

When a PDF or PostScript file is created, font names are sometimes compressed or renamed internally. In many engineering documents (AutoCAD, MicroStation, or older PDF generators), missing Asian fonts are generically labeled as . These are placeholders for specific CID fonts like: