When creating a PDF file and using Microsoft Sans Serif font at size 11, either from acrobat or word, Acrobat displays the uppercase M characters thicker than any others.

Interestingly, this only appears to happen when viewing the document at 100% zoom. 2 other PDF viewers don't have this issue, so I'm suspecting it has something to do in the manner Acrobat renders the font.

to the recipients of our files, it appears we are intentionally bolding the uppercase M's. I've raised this with Adobe support and they suggested adding this here as a bug report.

I've attached a file that displays the problem.