Lex regularly amazes me with his attention to detail.  Tonight he asked me why comics always write in uppercase.  Then he commented that in the Calvin and Hobbes books Moe always speaks in lowercase and bold.  Everyone else speaks in uppercase. Why is that?! Then he reminded me of a conversation we had years ago about why comics never use periods. They use question marks and exclamation points, but rarely use periods.   And he wondered what font Randal Monroe uses in xkcd comics.  His attention to detail astounds me.