Beyond craftsmanship and making handoff more efficient, we hope leading-trim will turn a new page for digital typesetting, eventually motivating improvements to other standards and platforms, starting with OpenType.
Leading-trim works by browsers accessing the font metrics to find, for example, the cap height and baseline. As the standard font format, OpenType specifies what metrics to include in the font file. OpenType has been jointly developed by Microsoft and Adobe as an extension of Apple’s TrueType font format since 1997. While today OpenType has robust support for Latin scripts and CJK languages, it still lacks key metrics for other less commonly used writing systems such as Hebrew or Thai. As people adopt leading-trim, we hope this leads the way for us to add more font metrics of other writing systems to OpenType.
Ultimately, we hope leading-trim helps improve OpenType and its internationalization by ensuring equal typographical capabilities across the world. That’s just the start of the ecosystem. Once leading-trim becomes available in all the modern browsers, desktop applications that are built using web technologies, such as Figma, Teams, and VS Code, will also be able to utilize it.
The impact can also go beyond the web. Sketch has already added snap targets for cap height and baseline. Instead of holding down the Option key to show bounding box to bounding box spacing, you can hold down Control + Option to see baseline to cap height spacing. It makes measuring optical spacing a lot easier. More importantly, this shows the slow shift in the way people approach digital typesetting. We are hoping leading-trim can further encourage this change. And through this mindset change, beyond just snap targets, leading-trim might just become a new text rendering standard in our design tools and extend to our operating systems.