Parametric fonts are cool. I think it's a stretch to say things like "Opening up to a new era of type design" though. Yes, the feature of "variable fonts" was added to the OpenType specification somewhat recently, in September 2016. But before that there was Adobe's "multiple master fonts", and even before that, there was Knuth's METAFONT, something that <i>could</i> have been a truly "new era of type design" but never took off.<p>See <a href="http://www.metaflop.com/modulator" rel="nofollow">http://www.metaflop.com/modulator</a> for an example of parametric fonts, inspired by Knuth's system: you can drag the sliders to adjust various font parameters, and get many different fonts. Knuth's article <i>The Concept of a Meta-Font</i> [1], published in <i>Visible Language</i>, is a classic. As you read the article he plays various tricks with the fonts as he describes them; it's a delightful read. (His followup article "Lessons learned from Metafont" [2] is also interesting.)<p>Unfortunately METAFONT as envisioned by Knuth never gained much adoption by other font designers, for (AFAICT) two reasons:<p>1. Douglas Hofstadter wrote a response [3] pointing out that it is not possible to mechanize all typefaces into a single one, which although a valid point (the article is great), attacks a straw man, arguing against an absurd claim that Knuth never even suggested IMO. So some may have got the wrong impression from it.<p>2. More importantly, as Richard Southall or Chuck Bigelow (I forget who) said, most type designers think with shapes; they don't think about shapes. Only a mind like Knuth's would prefer to think deeply <i>about</i> the shape of each letter and come up with symbolic descriptions of each, parametrized across the whole family (see Knuth's article <i>The letter S</i> [4] on his struggles with doing this for just one character).<p>Knuth has often said that we understand things better when we can teach them to a computer, and I still have hope for a future with parametric fonts that are better "understood": not because the shapes will be better, but simply because humanity will be better off with a deeper understanding of letterforms. But I think that whatever the technology, the task of parametrizing shapes will run into similar challenges, some of which were described in the above-mentioned articles and say Richard Southall's <i>Designing New Typefaces with Metafont</i> [5].<p>[1]: <a href="http://www.zigzaganimal.be/elements/the-concept-of-metafont.pdf" rel="nofollow">http://www.zigzaganimal.be/elements/the-concept-of-metafont....</a><p>[2]: <a href="https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/19.1/lessons-learned-from-metafont.pdf" rel="nofollow">https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/19.1/...</a><p>[3]: <a href="https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/16.4/meta-font-metamathematics-and-metaphysics-comments-on-donald-knuths-article-161.pdf" rel="nofollow">https://s3-us-west-2.amazonaws.com/visiblelanguage/pdf/16.4/...</a> / <a href="https://www.cs.indiana.edu/pub/techreports/TR136.pdf" rel="nofollow">https://www.cs.indiana.edu/pub/techreports/TR136.pdf</a><p>[4]: <a href="http://www.cnd.mcgill.ca/~ivan/Papers/The%20letter%20S.pdf" rel="nofollow">http://www.cnd.mcgill.ca/~ivan/Papers/The%20letter%20S.pdf</a><p>[5]: <a href="http://i.stanford.edu/pub/cstr/reports/cs/tr/85/1074/CS-TR-85-1074.pdf" rel="nofollow">http://i.stanford.edu/pub/cstr/reports/cs/tr/85/1074/CS-TR-8...</a>