Hi these are top tips - where the solutions are pretty quick. :-)
The below is actually from text help advice but works across most read write software.
1. Image-Based vs. Text-Based PDFs
The biggest culprit is usually that the PDF isn't actually "text"—it's a photograph of text.
- Text-Based: These are created digitally (like saving a Word doc as a PDF). The computer knows exactly what a "T" is and where it sits on the page.
- Image-Based: These are often created by scanners or photocopiers. To the computer, the page is just one big picture of ink. Without Optical Character Recognition (OCR), Read&Write sees pixels, not words.
2. The "Z-Pattern" and Reading Order
Sometimes the text is there, but Read&Write reads the sidebar before the main paragraph. This happens because of the underlying tagging.
- Digital documents have a hidden layer that tells assistive technology, "Read this box first, then that column."
- If a PDF is poorly formatted (common with multi-column academic papers or brochures), that hidden map is a mess, and the software just follows the "physical" coordinates it finds, which might be nonsensical.
PS the z pattern bit above isnt so much of a problem as with most readers you can identify the specific text you want to read.
3. Non-Standard Fonts
If a PDF uses a highly stylized or custom font, the software might struggle to map the character shapes to actual letters. Similarly, if the space between letters is too tight, the OCR might see "rn" and read it as "m," leading to those "m-words" you might hear during playback.
I think this been the main problem though i have encountered 'drawn' text that wont read
4. Security Restrictions
Some PDFs have "Owner Passwords" or security settings that specifically disable Content Accessibility. If the creator locked the file to prevent text copying, they often inadvertently block screen readers and literacy software from "seeing" the content at all.