by Dominique Petersen
As a book designer, one of my pet peeves is authors putting two spaces after each period in their manuscripts.
The habit of using two spaces comes from a time when most typewriters used monospaced fonts. Adding an extra space after the period at the end of a sentence made the text easier to read.
Today, fonts on computers are proportional and the extra space doesn’t improve readability. In fact, it makes the text look like it is riddled with holes—especially when formatting the manuscript into the book in which the text is justified on both sides.