Source Han Sans goes variable

The world’s first open-source Pan-CJK typeface Source Han Sans is now available as a variable font.

In the early 2010s, Google approached Adobe with an ambitious proposal: they wanted us to partner with them on an open-source typeface supporting a broad swath of East Asian languages. As luck (or the zeitgeist) would have it, Adobe already had such a typeface in the works. The two companies decided to join forces to design and develop the world’s first open-source Pan-CJK typeface: Source Han Sans (released as Noto Sans CJK by Google). Today, Adobe is delighted to publish the family’s latest iteration, Source Han Sans Variable.

Source Han Sans has been continuously updated and refined since it was first released in 2014. Currently, it covers many region-specific glyph variants for Simplified Chinese, Traditional Chinese (Taiwan), Traditional Chinese (Hong Kong), Japanese, and Korean. It also includes Latin, Cyrillic, and Greek glyphs borrowed from Adobe’s popular Source Sans family, slightly modified to harmonize well with the CJK glyphs.

The file size that comes with the full set of 65,535 glyphs in the Source Han Sans Pan-CJK fonts can be cumbersome in most settings, especially web hosting. One solution has been to use the region-specific subset fonts, but even those fonts can quickly become too large for efficient hosting. Furthermore, using the subset fonts does not help users who need to support multiple regions in the same document or website. That is where variable fonts really shine.

With the announcement of OpenType Font Variations in 2016, it was only a matter of time before existing fonts would adopt the technology — and that time has come for Source Han Sans. The existing seven weights of Source Han Sans now come in a single file that encompasses the entire design space. This affords typographers more granular control: rather than seven static weights ranging from ExtraLight to Heavy, weight exists on a continuum and is expressed through minimum and maximum numeric values. Designers can select any value in between, creating subtle typographic hierarchies and effects according to their needs.

This new format also decreases file sizes dramatically. For example, all seven fonts for a single region can be cut from 118 MB to 31 MB. The biggest savings, however, comes from the combination of variable fonts and OpenType Collections. The full set of static Pan-CJK Source Han Sans 2.002 fonts weighs in at 593.7 MB, but the matching variable fonts packaged as a single OTC file are only 32.9 MB. The regional subset fonts are even smaller. For instance, the seven Japanese subset static fonts totaling 32.1 MB weigh only 8.1 MB for the OTF variable font. This can be compressed even further to 4.1 MB as WOFF2.

Although Source Han Sans Variable represents only a minor update to the previous 2.002 release in terms of design and features, it is a major update on the level of footprint and performance. This release extends what was already an accessible, multiscript gothic sans serif that worked well both in print and on screen into an even more nimble, highly performant typeface. The Adobe fonts can now be downloaded from GitHub, as can Google’s version of the family, Noto Sans CJK Variable.