I’m often asked about Font Subsetting when exporting and creating PDF files using Distiller or directly from InDesign, so I thought I would post this explanation of what Font Subsetting is. When generating a PDF, it is possible to include only those characters in a font that were used in the document. This partial font is called a “Font Subset”. You adjust font subsetting in either the Acrobat Distiller job options or InDesign’s export dialog under “Subset fonts below X%”. The percent represents how much of the font is used in your document before it gets embedded in the PDF file. So a setting of 100% would mean that the entire font would be subsetted in the PDF file, while a setting of 5% would mean that you would have to use nearly all the characters available before the font would be subsetted. The primary advantages of subsetting fonts are that it not only reduces the PDF file size, but RIP’s (raster image processors) are forced to use the subset font even if the system has the full font available. Your PDF is slightly larger than other PDF files, but is also less likely to have problems with substituted fonts when output. Disadvantages of font subsetting are that it prevents your output provider from making edits to the PDF file if necessary, while still maintaining font integrity.