When you see a PDF listing fonts simply as "F1" or "F2," these are internal object names. The PDF creator (software like InDesign, a PDF printer driver, or a library) assigned these temporary labels to the font resources.
The problem arises when the mapping (the CMap) gets corrupted, or when the font is subsetted (partially embedded) incorrectly. This leads to text that looks like "tofu" (□□□) or printing errors. cid font f1 f2 f3 f4 repack
In corrupted workflows, you will see placeholders like: When you see a PDF listing fonts simply
These are fallback tags. When a PDF distiller cannot resolve a font’s actual PostScript name (e.g., "KozMinPro-Regular"), it assigns a generic handle: F1, F2, etc. The problem? If you move the PDF to another machine, the "repacked" CID mapping breaks, resulting in tofu blocks (□) or garbled text. The problem arises when the mapping (the CMap)
What is a CID font repack?
CID (Character Identifier) fonts are used in PostScript and PDF for Asian languages (Chinese, Japanese, Korean).
F1, F2, F3, F4 are internal font keys/subfonts in some RIPs or printers (e.g., older AdobePS, Kyocera, or Fiery).
A repack rebuilds or merges these font components into a working CID-keyed font file after extraction or corruption.