Hyphens, En Dashes, Em Dashes

Q. Dear CMS, I am nearly done revising my dissertation, but my advisor may not pass me on account of my lengthy em dashes! I am using Times New Roman, and apparently the em dashes are too long. Is the standard em dash in Times acceptable for thesis publication? If so, can I point my advisor to something in the CMS on this? (I am serious. I don’t think she would not pass me, but she has circled every em dash and said, “Too long. Fix!” on my drafts, and I’d like not to chance it.)

A. Well, that’s pretty crazy. For publication, it makes no difference what font is in the manuscript—typesetters follow the publisher’s specs, not a Word document or printout—but it looks as though you might have to change the font for your dissertation. Palatino has shorter em dashes than Times Roman, for instance. If you are required to use Times Roman, then change only the dashes to Palatino and maybe no one will notice. You can make a global replacement. Good luck!