This is a common practice in signs. It's wrong in literary English, but is it wrong in signs? My pet theory is that quotes for emphasis were popularized in 20t

This is a common practice in signs. It's wrong in literary English, but is it wrong in signs? My pet theory is that quotes for emphasis were popularized in 20th century movie posters, where it was common to surround the movie title in quotations (this is still the accepted citation style in, say MLA style). This is probably wrong, of course. Italics or bold for emphasis can be hard to hand-write, and the quotation marks for emphasis probably look more legible on chalk signs.