The beginning of Roman writing was the Majuscule letter, and every designer needs to try the magnificent Roman Majuscules. Not just the regular capitals that work with text lowercase, but the original inscriptional letters that were carved in stone in the days of the Republic and Empire.

The graceful proportions of the Majuscules let each letter have its own width; generally, single-story letters want to fit nearly to a square, two-story letters want to fit in half that square. The variety of widths brings a helpful distinctiveness to texts, and creates a pleasing rhythm that increases readability. In addition, the three basic shapes --square, circle, and triangle-- are used in combination with each other to create a variety of curves and angles that helps distinguish each letter from another. My favorite letter is the R. Why? it displays a version of each of the three shapes; it's the only letter to do this.

SPQR is, of course, uppercase only; with repeats at each lowercase position.