The accessibility of PDF (Portable Document Format) files is something of a bone of contention within the accessibility community, and an ongoing source of frustration among those working to improve document accessibility in their own organisation or industry.
The document format can be complicated to make accessible, and has many known issues—such as being difficult to correctly tag page elements, being incompatible with screen reading software, and jumbling up the read order from the source file.
But, imagine the accessibility challenge that occurs when you embed an inaccessible Illustrator file inside a PDF then try to make the whole document accessible.
Let’s illustrate this with an example.