OpenType Variable Fonts: Moving Right Along
by David Berlow
The OpenType Font Variations format includes a broad range of standard variables: weights from heavy to light, widths from wide to narrow, optical sizes from small to large, contrast, serif slope, and a few others which are currently on the drawing board.
This demo variation font includes a “Weight” axis that lightens without change horizontally or vertically, to the white space, and darkens the same way, without decreasing the white space, just changing the black, and the widths of the glyphs. (figure 1)
Amstelvar also contains a “Width” axis, that reduces the transparent (white) shapes and spaces of the letters only, leaving the opaque (black) to the variations of the weight axis alone. Between these two, what I call “single parametric axes,” the “normal” weights and widths of a font family are found, along with the grades, which are different weights on the same metrics. This is currently a single-pole axis, i.e. from the default font, it only gets narrower. (figure 2)
A third axis, contains another, currently single-pole axis, usually called “Contrast” that alone, just varies the lighter horizontal and diagonal parts of the glyphs. These three together lend optical size capabilities to the uppercase, figures and most of the punctuation in a Latin script design, (figure 3)
To enable optical size capabilities for the lowercase, an “xHeight” axis is also present in Amstelvar, an axis for the descenders and ascenders is planned to complete the variations required for the composition of this family in text and display settings with any reasonable or unreasonable amount of line spacing. (figure 4)
Pardon our font’s appearance out here on the frontier—we don’t typically show a typeface in progress. Most Font Bureau designs spend at least a year in the studio before we introduce them to the public.
We’re doing things a little differently with our latest project, which was sponsored by our friends at Google. For the past month, we have been working on a new OpenType variations font with Dave Crossland and the Google Fonts team.
And a “serif rise” axis has been included to simply experiment with the serif bracketing opportunities of this design for both low resolution rendering improvements, and to see how far a change of serif design can go in redefining the font family, within a variation space. (figure 5)
With this type and technology being made for users, despite the early stages, it never hurts to do more than just think about what kind of uses, beyond sliders and movies, these fonts might be put to. Variations in document composition for the web is one such area we’ve been working on and communicating about to the CSS working group on fonts.
On the web, using many long and cumbersome font names is not likely to last once users realize they can define the font styles in their web code the same as ever, or relative to other styles of a variation they are using, or relative to the default master of a variable font.
So the last illustration is of typography in variations, as it might need be to cross platform, rendering, or resolution boundaries, to work better with non-latin scripts, and in a variety of colors on a variety of backgrounds, and to suit other variables of web publishing. (figure 6)
Although we are in the early stages of the resurrection and expansion of font variations technology, it’s important that we do more than merely think about the manifold applications where these fonts may be used. Because far beyond sliders and movies, there is an expanse yet to be discovered.
For content developers, making the layout of text with deep hierarchies straightforward and responsive in web and presentation typography can also increase the quality of their results. Making an end user’s reading experience special—without their understanding why—can be facilitated in the future by designers using variations-aware applications and variable fonts.
For application developers, this kind of variable font and its technology offer a streamlined technical interface to some of the most popular features and styles useful in typography. We hope this will lead to simplified interfaces for both end users and web engineers, making much more powerful typography realizable.
In the meantime, we experiment, sometimes driving this technology to extremes to create the most interesting and useful typographic tools and variation fonts for end users and developers.
About the Design
For this type design, dubbed Amstelvar, I chose to work within the old style, transitional, and modern serif classifications based on Crossland’s request for a sloped serif. Sloped serifs work on all sorts of typefaces, but I wanted to distance this design as far as I could from Skia, the first QuickDraw GX font, which Matthew Carter drew for Apple in the early 1990s. He had this great idea for a design that he felt would lend itself well to variations technology. Skia was composed mainly of straight lines, broad curves, and terminals ending perpendicular to the strokes, minimizing the number of off-curve control points at angles to the underlying grid (as opposed to those points being horizontal or vertical).
To say that I chose to work in a more “traditional” type style would be misleading, as no well-recorded western design is much older in style than Skia, a design inspired by Greek written forms from the last century BC. So traditional, in this sense, actually means that the types of The Netherlands and Belgium from the sixteenth century forward to the development of Times Roman in the 1930s preceded the reintroduction of ancient Greek styles into fonts.