For those implementing PDF generators or managing large font libraries:
Over time, fonts were updated on artists' machines, but the old F1 references remained in the PDFs.
If your document contains Chinese, Japanese, Korean, Arabic, or specialized mathematical symbols, standard 8-bit fonts will break, resulting in unreadable squares (often called "tofu"). CID fonts are the only reliable way to ensure complex scripts render perfectly on any device. 2. File Size Efficiency (Font Subsetting) Winner: CID Fonts cid font f1 f2 f3 f4 better
If your audit shows that F3 or F4 are "Not embedded," re-export your source document. In InDesign, ensure "Subset fonts when less than 100% of characters are used" is UNCHECKED for critical documents. For shared PDFs, check explicitly.
The appearance of in your PDF is not inherently bad. It is simply evidence of complex, multi-font CJK rendering behind the scenes. However, default handling of these labels is often sloppy—leading to missing fonts, bloated files, and printing disasters. For those implementing PDF generators or managing large
Traditional fonts are limited to 256 characters. CID fonts bypass this limit by using an index of numbers (CIDs) to map out and display tens of thousands of glyphs. Today, this technology is also widely used in standard PDF creation to subset fonts, keeping file sizes small while maintaining visual layout consistency. Decoding the Labels: F1, F2, F3, and F4
. If the document was sent to you, the simplest and most reliable solution is to request a new PDF with all fonts properly embedded. For shared PDFs, check explicitly
Today, CID font technology is deeply integrated into OpenType fonts ( .otf ) and is a standard way PDFs embed complex, multilingual, or highly customized typefaces. What Do F1, F2, F3, and F4 Stand For?
Re-generate the PDF using "Print to PDF" (not "Save As") from your source application (Word, InDesign). This often collapses F1-F4 into a single, coherent font reference.
If a document requires both Latin characters and Cyrillic characters using a standard F1 font, conflicts arise. The font does not inherently know which code page to reference without complex re-encoding, often resulting in "garbage characters" (mojibake).