Transitional Serif

As we move further away from type’s calligraphic roots, contrast increases and the stress axis turns more upright and variable within each typeface rather than staying consistent as it does in the Humanist serifs. Letters in these typefaces are more regular in shape and proportion and apertures are slightly smaller. Transitional serifs still have a gradual, bracketed transition from the stem, and terminals are often bulbous.

Rational Serif

At the opposite end of the spectrum from the Humanists. Rational serifs have a strong, vertical contrast between thick vertical stems and fine horizontal hairlines. Because these typefaces are not so much written as constructed, their letterforms are very even in proportion and structure. Serifs are generally symmetrical, and can be bracketed, like Melior and Miller, or thin and abrupt, like the Didones (Bodoni and Didot).