Letters showing dark and others light

[Ben27992774vjf0]

Hi,

Im using AutoCad and producing PDFs, The text on my PDF seems to show very weirdly, Some letter in a paragragh of text will be dark and normal and others will be a light gray and difficult to read? 

Any help and advice would be great, I know its not the text itself as i can review the same document in a different PDF software without issue?

Many Thanks,

Ben

[Thomas297113583ii4]

We have this same problem and think it's because the CAD program's font is very thin.  When zoomed in, the letters become clear and black, but Adobe doesn't know how to display them normally.  The closest thing to a solution I've seen on here is to make the font bold in the CAD program.