Fitting text in a frame (see “Copy Fitting Styles and Style Settings”) by simply scaling text is not always desirable. An alternative solution is to apply a narrow typeface when a line becomes too long. This switching between a regular and a narrow typeface as the user types the text can be automated with the following action.

For the example below, two fonts are available in the document: Micron-Regular and Micron-Narrow. The text uses a character style called 'Title' and the action changes the typeface of this character style if the user enters more than 25 characters in a variable called 'City'. The 'On Change' action is applied to this variable.