My interpretation of what you wrote is that you are looking at screen fonts, not optically-designed outline fonts. Screen fonts usually have a size indicator to represent what size they appear best at on a monitor. The associated outline font is not usually size-specific.

If you were to print out a line of type with that font selected and the outline part was missing, you would get type that would be very bitmapped.

George, you are correct about screen or pixel fonts, but I don't think Keith was talking about them, as HTF Didot and Cycles are made for print, not the screen.

Keith, you're right; type with optical sizes are sometimes made for particular point sizes. But they are suggestions; your hard drive won't explode if you set Didot 16 at 24 pts! And, as you said, while some of it is that no sane type designer would design for every possible size -- especially since now it is easier than ever to set type at something like 11.128 pts -- a big part of it is that optical sizes exist to give the designer flexibility and refinement but not to prescribe rules.

In fact, many typefaces with optical sizes eschew specific point sizes altogether, e.g. Robert Slimbach's Arno Pro (Display, Subhead, Text, Small Text, Caption) and the many typefaces like Farnham that have display and text cuts. While a number may indicate exact measure (and perhaps the type designer did most of the testing at that size), any typeface can be set at any size. But certain attributes may make a particular font more useful in certain size ranges than in others.

HTF Didot is a great example. If you were to use the 96 pt version at 9 pt, the fine hairlines would disappear (among other things), making it less readable. But there's no reason you couldn't use the 64 pt version at 92 pts for a bolder, stronger look, just as you could certainly use the 16 pt version at 11 pts if you were printing at an extremely high resolution or with little distortion from the ink. The best bet is to try them all out (and print them out, not just view them on the screen!) and choose the cut that fits the look and feel you want.

Christian Schwartz emphasizes this point nicely when discussing his Giorgio: "Because the contrast between thick and thin is so extreme, this family is offered in 4 versions for different sizes. For normal use with offset printing, we recommend using Small from 24 point up to about 45 point, Medium up to about 70 point, Large up to about 90 point, and XLarge for anything above 90 point, where its delicate serifs and hairlines look their best; however, for screenprinting, reversing out of a colored background, or on-screen use (to name just a few exceptions), these guidelines may not necessarily apply."

Greg, my thanks, but actually, Reed is correct.

Reed, thank you for your help on this. I'm almost a bit shocked I appear to have guessed correctly!

Who knew the world of type would be so exciting!

Best regards,

Keith

Fabricando fabri fimus.