The fastest adoption of font technology in history raises lots of questions

The web has changed the typographer’s role. Typographers no longer decide on typefaces, font sizes, line lengths, line spacing, or margins; they make suggestions via marks and instructions so that text can make those choices for itself, responding to the context of an unknown reader’s environment. And although typographers no longer have access to all of the finished proofs of their work for all of those environments, they can now suggest—along with everything else—variations suited for any environment that imposes undue pressure on a user's type.

That kind of detailed suggestion for composition can happen if the role of the type designer changes, too. The type designer, in partnership with the typographer, has to embrace a new model in working for the web, from one of making a few font styles of a typeface that are supposed to work over a wide array of conditions, to making fonts that have at least a proper value system—and, at best, typeface families that have both the proper values and the fluidity of the rest of the web’s variables, like size, line length, line spacing, margins, and the pages themselves.

When we talk about “proper values” for typeface families, we mean values in the font expressed in the same system as the values just listed, which give the typographer parameters that interoperate fluidly with every variable, from type size to page size. Type size to page size, with lines, line spacing, and margins in between, are the values typographers have always had and used for composition. These values were based on systems of measure culminating in point sizes per em, which itself was the source of all measures within the typeface family. Now, for the web, the em itself is the central measure, so parts of the em (or, in our system, thousandths of an em) integrate perfectly.

People often wonder what is being measured and expressed in thousandths of an em. The common recurring values within each style of a font family—the height of the uppercase, the stem weight that gives a style its overall heaviness, the depth of descent below the baseline, and any other recurring values responsible for the appearance of a style, and important to the fluidity of the composition—are measured and offered to the typographer for each typeface family. Those values (of both the heights and widths of everything inside the em, hooked up to the size, line length, line spacing, and so on of the em and outside of it) give typographers a whole new set of powers of suggestion to add to their composition of web type.

In this site, we micromanage that fluidity to demonstrate a variety of examples. These examples range all along the process, from the first decision made about the scripts and languages of a text, through family and style suggestion, and on to the various treatments associated with the composition of typography.