An Introduction to Variable Fonts
Everything you thought you knew about fonts just changed (for the better). Typography has always been a keen interest of mine, long before we were able to use fonts on the web. And while we’ve had the ability to that now for ten years, we’ve always been constrained by balancing the number of fonts we want to use with the amount of data to be downloaded by the viewer. While good type and typography can bring huge benefits to design, readability, and overall experience—include too many fonts and you negatively impact performance and by extension, user experience. Three years ago, an evolution of the OpenType font format was introduced that changes things in some really remarkable ways. Introducing OpenType Font Variations (aka ‘variable fonts’) As long as I’ve used digital fonts, I’ve had to install separate files for every width, weight, or variant that I want to use. Bold in one file, light in another, condensed italic another one yet again. Installing a whole family for desktop use might involve nearly 100 files. The variable font format is an evolution of OpenType (the format we’ve all been using for years) that allows a single file to contain all of those previously separate files in a single, highly efficient one. The type designer can decide which axes to include, and define minimum and maximum values. See the Pen Variable font, outlined by Jason Pamental (@jpamental) on CodePen. On the web, that means we can load a single file and use CSS to set any axis, anywhere along the allowable range, without any artificial distortion by the browser. Some fonts might only have one axis (weight being the most common), and some may have more. A few are defined as ‘registered’ axes, which are the most common: width, weight, slant, italic, and optical size—but the format is extensible expressly so that designers can define their own custom axes and allow any sort of variation they want to create. Let’s see how that works on the desktop. Just like before, but different One of the ways the new format preserves backwards compatibility with other applications that don’t yet explicitly support variable fonts is something called ’named instances’—which are essentially mapped aliases for what used to be separate files. So whatever the typeface designer had in mind for ‘bold condensed’ would simply map to the appropriate points on the variation axes for weight and width. If the font has been made correctly, those instances will allow the font to be installed and used in recent versions of Windows and the MacOS just like they always have been. If the application fully supports variable fonts, then you would also be able to manipulate individual axes as you see fit. Currently that includes recent versions of Adobe Illustrator, Photoshop, and InDesign, and also recent versions of the popular web/UI design application Sketch. Discovering the secrets of style To get all of the specifics of what a font supports, especially for use on the web, you’ll want to do one of two things: check the following website, or download Firefox (or better, do both). If you have the font file and access to the web, go check out Roel Nieskens’ WakamaiFondue.com (What Can My Font Do… get it?). Simply drag-and-drop your font file as directed, and you’ll get a report generated right there showing what features the font has, languages its supports, file size, number of glyphs, and all of the variable axes that font supports, with low/high/default values displayed. You even get a type tester and some sliders to let you play around with the different…
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