This article describes the best practices when creating a PDF file.
Windows and Mac Operating System
Don’t use custom typefaces or “fancy” bullets: they can trigger mapping errors in accessibility checkers.
Create your PDF in a document and then save that document as a PDF and edit the PDF using the free software. Make sure that you save your original document and only edit the PDF.
Use OpenType fonts, or Base 14 fonts: fonts like Helvetica, Times, and Courier standard font families (regular, italic, bold, bold italic). Base 14 fonts don’t need to be fully embedded, which can help significantly reduce file size. Bullets and other special characters should also be picked from these fonts.
Avoid extra bold, black, or heavy font variations: these styles can cause text to appear multiple times in the document.
Don’t use small caps: Using small caps can cause text to appear as a mix of capitals and lower case characters in tags and cause the screen reader software to ‘stutter’.
Avoid double-page spreads: headers, body text or tables split into two pages are seen and tagged as separate pages by Adobe Acrobat.
Use embedded, flattened .jpg files: In files with layered graphics, like Illustrator drawings, and multiple layers of background shading, tagging can change layer order and cause text to disappear behind shading.
Simplify tables: Multiple levels of row/column headers are very difficult and labor intensive to tag. Even when structured and tagged perfectly, many screen readers will read them row by row, making them difficult for a non-sighted end-user to decipher.
Avoid using graphic elements or color coding to convey essential information. Differently colored or formatted words (such as bold, italic, etc.) need to be separated and tagged individually and supplied with alternate text.
Use ALT text: All graphics and relevant visual elements need descriptions that can be read by screen readers.
Be careful with file extensions: Always save Word documents as .doc then output as PDF.