It’s funny how when you are writing/developing course material, you realise you’re never 100% certain about the facts 🙂 and I hate writing things down when I’m not 100% sure. So, here I found myself — the Adobe Certified Expert and print specialist — digging back into the archives, looking more in-depth at font embedding and subsetting in PDFs, pros and cons as well as significant differences.
Most people might not realise that InDesign also subsets fonts, and even has a preference setting controlling when fonts are to be subset. By default any font with a glyph count greater than 2,000 will subset fonts (Preferences > General). That is… embed only those glyphs that are used within the document. Distiller has an additional percentage setting that is called to determine when font-subsetting occurs. Font subsets are send to the PostScript stream under their own name preventing unwanted font substition at output end. Where PDF size is important, subsetting will result in smaller PDF file sizes in comparison to full font embedding.
Web Reference: Adobe InDesign CS2 Print Guide for Prepress Service Providers (8.2Mb) (2006, Adobe Systems Inc.).
Web Reference: Font Handling in Acrobat Distiller – Support Knowledgebase (2006, Adobe Systems Inc.)