Variable fonts are a new type of TrueType/OpenType font that allows an entire typeface family to be packaged as one small and powerful file. The font maker creates a small number of “master designs”, representing the key design stages of the typeface, leaving the generation of all the in-between fonts to the font rendering system. By embedding a Thin master and a Fat master in a single variable font, and also storing a number representing where each master sits on on a “weight axis”, we get thousands of intermediate-weight fonts for free, all of them mathematically interpolated from the masters. A “width axis” works similarly, letting the user summon everything from Condensed to Expanded. Multiple axes work together, so we get Narrow Thin, Expanded Semibold and literally millions of other variants. The user is free to choose any of the possible axis settings, but to keep things manageable the fontmaker gives friendly names to recommended settings — so-called “Named Instances”.