Older HP or Xerox printers with PostScript Level 2 interpreters used the F1 family as a fallback when no specific CJK font was installed locally.

If you generate PDFs programmatically (via iText, Prawn, ReportLab, or PyPDF2), you can avoid the dreaded "F1 Family" fallback by following these best practices:

Is the CID Font F1 Family obsolete? Not entirely, but its role is shrinking.

Prediction: Within a decade, the "F1 Family" will exist only in digital forensics and legacy document parsers. It will be the typographic equivalent of a 5.25-inch floppy disk—recognizable only to engineers solving compatibility emergencies.