The double spaces after a period argument has been debated ad nauseum, just do a quick search and you’ll see. Even the “experts” disagree on this topic. Which is why, as someone who grew up using typewriters and the first word-processors, and as both a grammar/punctuation fanatic and a professional designer and business owner, I’m here to clear it up!
Back when typewriters were the only alternative to hand-written pages, type was mono spaced. This means that every key took up the same amount of space, whether it was an “i” or an “m.” It sometimes made it difficult to visually determine a pause in a sentence, which is indicated by a comma, from the end of a sentence, indicated with a period. It also meant that sometimes there were larger and smaller spaces between letters. So, for no other reason than to improve visual readability, it became common practice to use two spaces after a period when using a typewriter. The space following all other punctuation was still a single-space.
It’s important to note here, that in offset printing, no double spaces were used. Older printing was “set” using individual letter blocks that were set one-by-one in a press. These letter blocks already accommodated for the differences in the width of letters and appropriate spacing after punctuation, so no double-spacing was required. The double spacing was solely for the purpose of legibility on typewriters. Additionally, having a single space shortened the overall text, and decreased printing and paper costs. Some say this also lead to the adoption of single-spacing.
Along came the first word-processors. Some of which were glorified typewriters with some automated functionality, but they quickly evolved into something that closely resembles the word processing we use today. And here’s why that’s important – word processors and the computers we use today have proportional type. Proportional type means that the computer font already accounts for both the width of each individual letter, and the appropriate visual spacing after punctuation. So there is no longer any need to add that old-fashioned double space. In fact, because it is already accounted for, adding a double space is adding much more space than is visually necessary and creates visual “rivers” through a block of type. (more…)