I’m surprised how often I see all caps in a presentation or other marcom material. There are very good reasons not to use them, except in very limited cases.
But first a little personal computing history. When I attempted to learn programming languages, including BASIC and Cobol, in the late 70’s EVERYTHING WAS ALL CAPS on timeshared mini-computers! Thus when I bought my first personal computer, an Apple II, I wasn’t surprised at all that the keyboard had only caps, not lower case. Steve Wozniak saw no need for lower case, as he assumed users would be either programming or playing games, neither of which needed lower case. Eventually the market demand for lower case delivered an add-on, I can’t remember it’s name or how it worked, but Apple Computer, Inc didn’t deliver a computer capable of lower case until the Apple III. Unfortunately for those of us who like to use both upper and lower case, the Apple III with it’s spacious 80 column screen (the Apple II only offered 40 columns of text) was a turkey and I heard that many of them ended up in landfills somewhere! Oh wait, maybe that was the Apple Lisa!
At any rate in 1981 with the IBM PC the market finally had a machine with a full keyboard, 80 column screen, and upper and lower case. The rest is history.
So what’s wrong with using ALL CAPS! I’m only an amateur when it comes to fonts and human perception. But here’s my two cents:
- All caps are very intrusive. They are good at getting your ATTENTION. Thus they are commonly used on STOP signs or warning signs like on the MBTA trains: WATCH YOUR STEP. Thus using all caps on an extensive string of text will really be felt as very intrusive by your reader.
- Upper and lower case enables us to differentiate proper nouns like names, and titles: President Donald Trump, from other text surrounding the proper nouns. By using all caps this important differentiator is lost.
- All caps look like monospace text like this the Currier font, which imitates a typewriter. Monospaced type is much harder to read as it lacks kerning, the process of adjusting the spacing between characters in a proportional font, usually to achieve a visually pleasing result
So if you want to get your reader’s attention, do use all caps, but very sparingly, just as you should use bold, underline, or italic sparingly.