When to use what font variation (extralight, semilight, semibold, extrabold...)?

pers0n24 February 2010 · 09:07

I've seen fonts use these kinds of variations:
ExtraLight
Light
SemiLight
Plain/Regular
SemiBold
Bold
ExtraBold
Black

and I was curious when to use which. Now I've seen someone say to use SemiBold when using white on a black background. And of course I know to use Bold when trying to emphasize something or Light if its something that needs to be airy, of if the font-size is really huge, and perhaps Black if its something that really needs to stand out.

Also I was curious about the number sizes I've seen also:
100 = ExtraLight
200
300
400
500
600
700
800
900 = Black

Does 500 = regular?

Theunis de Jong24 February 2010 · 12:47

Semibold on reversed background: this is because of human perception. A regular font in reverse looks lighter than when viewed "normally". There is at least one font that comes with 'normal' and 'reverse' versions, where the to-be-used-in-reverse version is ever so slightly more bold than the regular variant. (Oh, brain! Come on! (thump, thump)... nope.)

As to when to use what variant ... Whenever you like, I'd say. I can set a book title extra black and very small, or large and light ... or exactly the opposite. Whatever looks best. Period. (Generally speaking, a small bold title with a large black subtitle does not look good.)

I think the numbering scheme was designed to work around made-up weight names -- i.e., "Semibold" or "Demibold"? "Regular" or "Medium" or "Book"? MS Windows pretends to use the numbered Weight for selecting an appropriate font, but actually it doesn't -- I always got Regular for a value around 500-ish and lower, and Bold for anything higher, and never a Light or Semibold or Black font. Mind, that's pre-Windows 7 -- word on the street is WPF has a better "fitting" algorithm, but I haven't used that as yet.