The link he gives there isn't his own site, it's an online typography ebook by Matthew Butterick, a professional typographer. I expect most of the knowledge in

The link he gives there isn't his own site, it's an online typography ebook by Matthew Butterick, a professional typographer. I expect most of the knowledge in his comment comes from there as well. It's worth a read: http://practicaltypography.com/ http://practicaltypography.com/