Before we tackle the F1...F6 suffixes, we must understand the container. CIDFont (Character Identifier Font) is a font format standard developed by Adobe for PostScript and PDF. Unlike simple fonts (Type 1) that use 8-bit character codes (256 glyphs max), CIDFonts are designed for large character sets:
A CIDFont system consists of two parts:
When a PDF is created, the PDF writer often needs to subset the font (only include the characters used in the document). To do this efficiently, it renames the font internally.
gs -dSAFER -dBATCH -dNOPAUSE -sDEVICE=pdfwrite \
-dEmbedAllFonts=true -dSubsetFonts=false \
-sOutputFile=output_fullfonts.pdf \
-f input_with_F1_F6.pdf
The terms F1, F2, F3, F4, F5, and F6 are not model numbers or specific font styles. They are arbitrary internal variable names used by the PostScript and PDF languages to point to font resources.
When these identifiers are paired with CIDFonts, they represent the complex mechanism required to render large character sets (CJK). Understanding that these are simply pointers allows developers and print professionals to debug font errors more effectively—realizing that the error lies not in the name "F1," but in the font data to which F1 points.
This text usually appears in Adobe Acrobat or Illustrator as an error message indicating that a PDF file contains "phantom" or missing embedded fonts. What the text means
CIDFont: Refers to a "Character Identifier" font, a format often used for large character sets (like Asian languages) or specific PDF encoding.
F1, F2, F3...: These are generic placeholders used by PDF generators when the original font name is not properly embedded or recognized. For example, F1 might be mapped to Arial Bold, while F2 is mapped to Arial Regular.
Full: Indicates that the full character set is supposed to be present, though the system cannot find the specific font file to render it. Common Solutions
If you are seeing this error and the text is appearing as dots, boxes, or scrambled characters, try these fixes: cidfont f1 f2 f3 f4 f5 f6 full
Print to PDF: Open the file in a browser (like Chrome) or a basic viewer like macOS Preview, then choose File > Print > Save as PDF. This often "flattens" the fonts into a more readable format.
Adobe Acrobat "Print as Image": In the Adobe Print dialog, click Advanced and check the Print As Image box to bypass font rendering issues.
Import into Illustrator: If you need to edit the file, try importing it into a new document rather than opening it directly. You can then use the Transparency Flattener to convert the text to outlines.
Check PDF Properties: Use Ctrl+D (Windows) or Cmd+D (Mac) in Adobe to view the Fonts tab and see exactly which fonts are listed as "Embedded Subset" or "Missing". Are you trying to fix a file with this error, or CID+ Fonts - Adobe Community
2 Oct 2018 — The font CIDFont+F1 is Arial (blod) and CIDFont+F2 is Arial (Regular) CID+ Fonts - Adobe Community
The string "cidfont f1 f2 f3 f4 f5 f6 full" typically appears when a PDF viewer or editor (like Adobe Acrobat or Affinity Photo) encounters a document with missing or poorly embedded fonts. In PDF technical terms:
CIDFont: Refers to "Character ID Fonts," a method for handling large character sets, such as those used in Asian languages or complex Unicode documents.
F1, F2, etc.: These are generic internal aliases (tags) assigned by the software that created the PDF. They do not reveal the original font name (e.g., Arial or Times New Roman) but represent specific font styles used in that document.
Full: Often indicates that a font is supposed to be "Fully Embedded" rather than just a subset of characters. Common Issues Before we tackle the F1
If you are seeing these names, it usually means your system cannot find the specific font files required to display the text correctly. This often leads to:
Missing text: The document opens, but the text is blank or appears as dots/boxes.
Error messages: Alerts like "CIDFont+F1 cannot be created or found".
Mangled rendering: The text displays in a generic replacement font that may mess up the layout. How to Fix Impossible fonts to be found / Fontes impossíveis de achar
The phrase " CIDFont F1 F2 F3 F4 F5 F6 " typically appears in PDF documents when the software used to create or export the file could not properly embed the original fonts. Instead of using the actual font names (like Arial or Times New Roman), the PDF uses these "CIDFont" placeholders as generic substitutes. Creative COW Common Meanings for these Codes
In many cases, these placeholders correspond to specific font styles or weights: CIDFont+F1 : Often represents Arial Bold CIDFont+F2 : Often represents Arial Regular F1 through F6
: These labels generally define different font weights or styles (e.g., italic, light, black) assigned by the exporting software. Why You See This
You usually encounter these names in error messages or "Missing Font" warnings when opening a PDF in programs like Adobe Illustrator Affinity Designer Adobe Acrobat Missing Data
: If the PDF was not "fully embedded," your computer won't know what these fonts are supposed to look like, leading to text displaying as dots or garbled characters. Substitution A CIDFont system consists of two parts:
: If you see "full" in your text string, it likely refers to a "full subset" embedding, meaning the entire character set of that generic font is included in the file. Super User How to Fix Font Issues If you are trying to view or edit a file with these names: Transparency Flattening Adobe Illustrator , try importing the PDF and using the Transparency Flattener
to "create outlines." This converts the text into shapes so you don't need the font. Use "Preview" (Mac) : Opening the PDF in Apple Preview
and re-exporting it as a new PDF often fixes encoding issues and makes the file readable. Check Properties ) in Acrobat to view the
; this will show you which "actual" fonts the CIDFonts are trying to replace. Are you trying to fix a broken PDF or are you a document and need to define these font names manually? Impossible fonts to be found / Fontes impossíveis de achar
It seems you're asking for a review or explanation of CID fonts (Character ID fonts), specifically looking into variants labeled F1, F2, F3, F4, F5, F6 — possibly in the context of PostScript, PDF, or printer firmware (like Canon, Ricoh, or HP’s implementation of CID-keyed fonts).
Here’s a structured breakdown:
The sequence F1, F2, F3... is simply the standard naming convention used by PDF generation libraries (like Adobe Distiller, Ghostscript, or PDFKit) when encoding a document.
If a document uses six different fonts, the PDF internal structure will label them F1 through F6. If it uses 20 fonts, it will continue to F20.
Run pdffonts again on the output. The "sub" column should now show no (meaning full embedding). CIDFont+F1 will now contain all glyphs.
Cause: The original PDF expects a font named exactly CIDFont+F2, but that name is only a reference.
Solution: Rename the font inside the PDF using a tool like cpdf (Coherent PDF) or use Ghostscript to re-embed with a standard base font:
cpdf -replace-fonts "CIDFont+F2" "NotoSansCJKjp-Bold" in.pdf -o out.pdf