I single-space after a period. Double-spacing comes from the days when we had typewriters, and the spacing was kind of gross because typewriters are mono-spaced, right? So that came from those days. I don't know any typographer who does a double-space after a period, the same way no typographer (or nobody who knows anything about type) would ever use underlining as a way of emphasizing, because you break the word shape. Underlining, again, is one of these things that hearks back to the days of typewriter (sic), because underlining was the only kind of emphasis you had. But in good typography, in books or magazines or whatever, people use italics or bold for emphasis, not -- never, never, never, never underlining. Underlining is something you do with a pen when you're reading something yourself 'cause it's an emphasis you can do, or something you do with a typewriter because it's the only one you've got, but never in typeset type, it shouldn't be [used]. I used to be an editor, a proofreader, at a paper in Scotland called "The Scotsman". "The Scotsman" is kind of a weird thing, I used to be a writer there as well; they did this once, there was a reading age required to read various newspapers. So they had "The Sun" -- if you're at the reading age of six, I think, you could read "The Sun". "London Times" I think you needed a reading age of at least eleven. "The Scotsman" you needed a reading age of thirteen; it was kind of the most erudite paper, and they were incredibly fussy about the typesetting, the way it was done. So you kind of learn that stuff, and the double-space is kind of ugly, because a space is not a fixed thing, right? Because, you know, once the application has ????? and then said "OK, I have to break this string here, I really have to hypenate this word, or route this word down to the next line. OK, now I have to space out, right? And spacing is one of those things that floats like that, so two spaces is compounding the floating-error of one space, so it's not a good thing to use. That's my story and I'm sticking to it