Spacing after a period

I recall much research into this subject has shown in the past that there is enough space above the punctuation points to make a single space sufficient. The use of a monospaced font certainly invalidates the research in my mind.

Of course we also have to consider the broken appearance of the double spaces, or for that matter, wide spacing of any kind in the readability of any typeset page. Whether regarded as influential now as when I was a student of typography in college, Miles Tinker’s studies demonstrated the efficacy of single spacing, and close spacing between words, as beneficial for readability.

John Henry
Cedar Creek Press

I like an en quad after a period, and usually 3-em spaces (going down to 4-em or even 5-em if I’m trying to justify both margins) between words.