Variable fonts, by and large, follow a file or files containing designs of one family. While it’s possible within a variable font to change families, many of the disadvantages of the past’s ‘one style per file’ are solved. Variable fonts containing styles for optical sizes can be engaged automatically via the specification of size. Variable font specification can be done in web design with transparent use of optical sizes as well as powerful automated selection of widths via font-stretch, and relative definition for weight and other axes, all from a file. And all of this can happen without the user fussing over a single style name.