In all my years of writing about type, it’s still the question I hear most often, and a search of the web will find threads galore on the subject.
I’m going to try to put an end to the argument here. But the use of double spaces (or other exaggerated spacing) after a period is a typographic convention with roots that far predate the typewriter.
Once you type a document and get the content how you want it, the finishing touches can sometimes be the most important.
An eye catching document will draw the reader in, while a boring font without a lot of extra details will draw the reader away from all your hard work.
Applying bold, underline, or italics when appropriate, can emphasize text.
You might find that having different font sizes in your document to denote various topics will also enhance your document.
To create that interest, Microsoft Word can help you change your document for a fresh look.
One of the first elements you can change is your font attributes.
I’m not prepared to aver that double spaces at the ends of sentences arose from crass commercial concerns, but I think it makes a quality rumor, and you can say you saw it here first.
Styles in all things change, and for reasons that are unclear to me, the habit of double-spacing faded away.