It is actually the opposite despite of the W3 standards. In typography, book weight for print fonts is usually lighter (congruent to W3 standards). This is bec

It is actually the opposite despite of the W3 standards. In typography, book weight for print fonts is usually lighter (congruent to W3 standards). This is because of the slight blotting effect when printed on paper. But for screen use, it is actually slightly bolder (450-ish). Here is an example from Lineto foundry: https://lineto.com/typefaces/moderne https://lineto.com/typefaces/moderne Book weight is between Regular and Medium.