Fonts in PDF
Fonts define how text appears in a document — including its style, weight, spacing, and overall readability. In a PDF, fonts are managed differently depending on how the file was created and exported. Understanding how fonts are stored and referenced is critical to ensuring accurate proofing and text extraction.
How Fonts Are Handled in PDFs
| Font Handling Type | Description |
|---|---|
| Embedded Fonts | The actual font data (or a subset of it) is stored within the PDF file. This ensures that the text appears the same on all systems, regardless of which fonts are installed. |
| System Fonts | The PDF references fonts that are expected to exist on the viewer’s device. If the required font is missing, the system substitutes another font, which can cause text appearance or alignment issues. |
| Custom Encodings | Some PDFs store characters using non-standard or customized encodings. While visually correct, these can make it difficult for extraction tools to interpret the actual text characters. |
Common Font Types Used in PDFs
- TrueType (.ttf) – Widely used; supports detailed hinting for screen readability.
- OpenType (.otf) – Advanced format supporting ligatures, extended characters, and cross-platform compatibility.
- Type 1 – An older Adobe PostScript-based format, still found in legacy documents.
- CID-Keyed Fonts – Commonly used for Asian languages; support large character sets and complex glyph structures.
Why It Matters for Proofing?
Missing, substituted, or incorrectly encoded fonts can lead to unreadable or garbled text when analyzed by proofing tools. This directly impacts processes like text comparison, spell check, and automated quality validation.
Our proofing system incorporates intelligent font-handling logic to interpret and normalize these variations. However, to achieve consistent and accurate results, designers should always ensure that all required fonts are properly embedded during PDF creation.