<p>I've used these quite a lot, but they only look nice on Word. once you put them in a college's essay submission box, it looks like this:</p>
<p>"johnny's face -- the one with all the scars -- did not look so good"
(random sentence)</p>
<p>should I leave it like that? or leave it at one dash (rather than two, as in this "--")</p>
<p>I don’t think it makes that much of a difference, but I would leave it as a double dash.</p>
<p>I would personally go back and edit all of those to one hypen. It saves characters and might look a bit neater. It’s totally up to you though. I personally found it awesome that you were willing to use hyphens in a college essay, just sayin’</p>
<p>On mac, option shift hyphen gets you the long dash. There may be something similar in Windows. In my opinion, the double dash looks terrible, and though this shouldn’t affect your admissions, readers are human too.</p>
<p>Personally, I think one dash does the job, you don’t need two</p>