Can anyone tell me what a proportional spaced font is?
Yep. "W" is wider than "i". "M" is wider than "j". Proportional spacing takes into account the space a letter takes and varies the space to the next letter accordingly so that a word doesn't look "jerky" with too much white space between letters - or have letters smashed together.
non proportional- all letters use the same line space.
I believe that in proportional spaced fonts each letter is centered in a square of space so that on either side there is the same distance between letters. With typewriters, it was often the case where some letters were closer to the edges of a key than others on a given machine...thus spacing appeared out of proportion depending upon which letters were side by side. This is also why in old detective movies/books you'll hear of matching a letter to the typewriter. Each key is manufactured with miniscule differences from one typewriter to another. With word processors/printers this was eliminated through programming.
The next time you post anything on FR, look at the "Your Reply" window, which you type in and the "If you posted your comment as-is, it would look like" preview window. The window you type in is evenly spaced. The preview window uses proportional fonts.
Try typing iiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiiii.
See how long that string looks like in the typing window and how short it is in the preview window? Pretty cool, huh?
The dead givaway that something is in even spaced fonts is the "i", the "j" and the "m". The narrow letters have these big, honkin' serifs whose only job is to take up space. The "m", OTOH, is so bunched up it is hard to read.
A proportional spaced font is one, like the most generally used Times New Roman, where the amount of horizontal space taken by each letter varies depending on the width of that letter. For example, a "W" is much wider than an "l" in a proportionally spaced font. A monospaced font, like Curier, deliberately makes the size of each letter the same.
Proportionally spaced fonts therefore allow printers to put more words on a line because the narrow letters are narrow and the wide letters are wide. Proporrtional spacing was very hard to put into typewriters because the gears that drove the machines would havee to be designed to provide different horizontal spacing depending on which letter the typist struck. Thus, it was much easier and vastly less expensive to make each of the letters the same horizontal size so the typewriter would only have to use a space of the same size as each letter key was stuck.
All of changed with computers, lazer, and ink jet printers, all of which easily do this with software, instead of mechanically.
You have some proportionally spaced fonts available to you on the computer. Courier is one. Write something in Courier and compare it to the same text written in Ariel.
Wish I could post examples for you but for some reason that is above my skill level on this forum.