A reader wrote to me last week with the following question:
"I am working on a financial report. The client has requested to have all commas line up as well as $ signs and keeping numbers right justified. I can't seem to do all three. I can get the number data right justified, and the dollar signs to match on a column but not the commas. Any suggestions?"
Upon further investigation, what she was encountering was this:
The commas don't line up because the typeface (Cambria Regular) is an OpenType typeface that supports proportional numerals. In other words, each numeral is a different width (the numeral one is narrower than the numeral eight for example). Most typefaces contain only tabular (equal width) numerals, so this isn't usually a problem.
Luckily, some OpenType fonts contain both proportional and tabular numerals, and InDesign and Illustrator allow you to choose which numeral style you want. Use the proportional numeral style to improve the spacing of numbers wherever possible, and switch to tabular numeral style to make columns of numbers align, as shown below.
To switch between tabular and proportional figures in InDesign, select the text with the Type tool, and choose OpenType > Tabular Lining/Proportional Lining from the Control panel menu. In Illustrator, display the OpenType panel (Window > Type > OpenType), and choose either Tabular Lining or Proportional Lining for the "Position".
To align the dollar signs in the example above, I inserted a "Figure Space" (Type > Insert White Space > Figure Space) in InDesign after the dollar sign on the last line. A figure space is the same width as a numeral when you are using Tabular figure alignment.