HOW TO CREATE VARIABLE FONTS: A GUIDE FOR TYPE DESIGNERS

Summary from the TLDR Design newsletter

Variable fonts are single OpenType files that contain continuous ranges of design variants, replacing multiple separate font files with one file that can interpolate between different weights, widths, and other characteristics. They use variation axes like weight, width, italic, slant, and optical size to provide infinite control over typography. Variable fonts have become the professional standard for type design, with 92% browser compatibility and adoption by 40% of websites, making proficiency in them a career-defining skill for type designers.