Vertical orientation of weight axes. (The vertical parts of letters are thick.)
Strong contrast between thick and thin lines. (Horizontal parts of letters are thin in comparison to the vertical parts.)
An unornamented, "modern" appearance.
Period examples include Bodoni, Didot, and Walbaum, while modern typefaces along the same lines include Computer Modern, Surveyor and Filosofia. It remains very popular in the printing of Greek, as the Didot family were among the first to set up a printing press in the newly-independent country, and in mathematics, aided by the status of Computer Modern as the default typeface of the mathematical typesetting programmes TeX and LaTeX.