; this can often "flatten" or re-encode the fonts into a usable state. Font Mapping : In professional design tools like Adobe Illustrator
The key is never to use the generic F1–F6 as final identifiers.
Instead, it is a placeholder created by a PDF viewer or editor when the original font used in the document was not properly embedded. stands for Character Identifier .
tool to manually replace the CIDFont placeholders with installed fonts like Check Document Properties Adobe Acrobat File > Properties > Fonts to see if the software lists the cidfontf1 f2 f3 f4 f5 f6 updated
When working with PDFs, particularly those generated from East Asian languages (Japanese, Chinese, Korean) or complex design software, encountering an error message citing or similar up to F6 is a common, frustrating issue. These errors often occur when opening a document in Adobe Acrobat, Affinity Designer, or other PDF readers, stating that the fonts are missing, causing text to appear as garbled characters, boxes, or missing entirely.
A review of online discussions reveals many users incorrectly identifying these placeholders:
| Error Message | Likely Cause | Updated Fix (2025) | |---------------|--------------|--------------------| | Cannot find CIDFont "CIDFontF3" | Missing monospace CID mapping | Install NotoSansMonoCJK or map F3 to SourceCodePro | | Invalid glyph width for CIDFontF4 | Old width table | Re-extract widths using ttx (fonttools) | | PDF contains non-compatible CIDFontF5 | PDF/A-3 violation | Convert to PDF/A-4 with embedded NotoSerifCJK | | CIDFontF6 symbols missing | Dingbat mapping broken | Use ZapfDingbats CID directly or switch to Unicode symbols | ; this can often "flatten" or re-encode the
: If you're using a web browser (like Chrome or Safari), try opening the file in Adobe Acrobat Reader . It has better support for CID font mapping [2, 4].
: When saving or exporting as a PDF, ensure the "Embed All Fonts" option is checked. This packages the font data inside the file so the recipient doesn't need to have it installed on their system [1, 3].
If a specific PDF printer driver is producing these errors, switch to a more modern alternative. Tools based on newer technology, such as or updated PDF24 Creator , often handle CJK fonts better than older legacy systems. 5. Convert Text to Outlines (For Designers) stands for Character Identifier
The single best way to avoid the CIDFont+F1 headache is to
Depending on whether you are trying to read a broken file or trying to create a file that others can read, use the following updated methods to resolve the issue. Method 1: Change Your PDF Reader (Fastest Fix)
To clarify, a well-constructed PDF will have entries like /BaseFont /Helvetica or reference an embedded font with a unique name. In a problem PDF, you would instead see lines referencing the CIDFont+F1 dictionary. This tells the PDF reader, "This text is supposed to be in a specific font, but I don't have the data for it, so I'm using this placeholder to maintain the text's structure."
When opening, editing, or converting a PDF document in programs like , Adobe Illustrator , Nitro Pro, or Affinity Designer, you might encounter an error regarding missing fonts named CIDFont+F1, CIDFont+F2, CIDFont+F3, CIDFont+F4, CIDFont+F5, or CIDFont+F6 .