“He strove to design a typeface that was timeless”
Ben Trissel, writing for Typekit:
Futura is built from geometric shapes—rectangles, circles, and triangles. Here, Renner used symmetry and proportion to his advantage: the ascenders on the lowercase letters are taller than the caps. The caps themselves are based on classic Roman type proportions. The counters are perfect circles, while the surrounding arcs are elliptical. The vertices on the lighter weight caps, like the ‘M’, descend just below the baseline.
The sum is a typeface that is gently propulsive.