First, let’s break down the acronym. CID stands for Character Identifier.
Unlike standard Western fonts (Type 1 or TrueType) that use a simple 1-byte encoding (mapping one number to one glyph, limiting you to 256 characters), CID-keyed fonts are designed for 2-byte encoding. This allows for over 65,000 characters – essential for languages like Japanese Kanji, Traditional Chinese, or Korean Hangul.
A CID font is actually a two-part system: cid font f1 f2 f3 f4
When you see "CID Font F1" in a PDF, the PDF is referring to a CID-keyed font subset embedded in the document.
In many Adobe PostScript printers, RIPs (Raster Image Processors), or PDF analysis tools, F1, F2, F3, F4 are Font Numbers or Font Indexes assigned to different CID supplements. They are not font names, but slots where the printer loads specific character collections. First, let’s break down the acronym
Here is what each typically represents:
| Identifier | Typical Supplement / Collection | Common Use Case | Character Set Size | | :--- | :--- | :--- | :--- | | F1 | Adobe-Japan1 (Suppl. 0-7) | Japanese (Kanji, Hiragana, Katakana) | ~8,000+ glyphs | | F2 | Adobe-GB1 (Suppl. 0-5) | Simplified Chinese (PRC) | ~8,000+ glyphs | | F3 | Adobe-CNS1 (Suppl. 0-7) | Traditional Chinese (Taiwan/HK) | ~13,000+ glyphs | | F4 | Adobe-Korea1 (Suppl. 0-3) | Korean (Hangul & Hanja) | ~8,000+ glyphs | When you see "CID Font F1" in a
/F1 10 Tf
(Hello) Tj
/F2 12 Tf
(世界) Tj
Here, F1 might be a Latin CID font, F2 a Japanese one.