In 2018, iA released three iA Writer fonts.
As of the time of this writing, November 6, 2022, there is an unfortunate metadata issue with iA Writer Quattro S. The bold and bold italic ttf files have a metadata error which can cause those styles to be applied incorrectly in some applications. See this issue on GitHub.
I updated the metadata of Quattro S Bold and Quattro S BoldItalic using FontForge and regenerated the font files as the creator of that issue suggested. I’m offering them for download here only because I’d love to see more use of Quattro and it takes a bit of technical savvy to make these fixes—which I suspect the average user will not know how or bother to do.
That said, I’m not an expert and I don’t know if I accidentally changed anything by regenerating the files. I’m offering them as-is for convenience only. You must abide by the license and by downloading and using these repaired files, you agree that you will not hold me responsible for any problems or damages you might encounter by using these files.