Non-Designer’s Type Book, The, Second Edition

Proportionally Spaced Figures

In most (not all) expert fonts, the oldstyle figures are proportionally spaced, meaning they each take up only as much space as is appropriate for the number —the number one takes up less space than a nine because it’s skinnier. This is particularly wonderful for text use because the numbers fit together so well, but don’t use proportionally spaced oldstyle figures in columns to be summed or they won’t line up! When you buy an expert set and start using oldstyle figures, first make a quick check to see if yours are proportionally spaced or monospaced: just type several rows in columns and see if you can draw a clean line between each column.

Because the numbers on the far-left are monospaced, they align neatly in ...