(Not) Using Auto Leading
Auto Leading is a relatively new concept, emerging with desktop publishing in the mid-1980s. Auto Leading allows InDesign to assign a leading value based on the type's point size. By default, Auto Leading is 120 percent of the type size, although you can change this in your Justification options. Leading values in parentheses indicate Auto Leading.
The best thing you can say about Auto Leading is that it's convenient. You can change your text size as often as you like and your type will always be readable. As your font size increases or decreases, so does your leading.
The largest leading value in a line of type determines the leading for the whole line, which means that the leading will be inconsistent if you inadvertently make one character bigger than the rest of the text. You can change this behavior in your Type preferences by selecting the Apply Leading to Entire Paragraphs option. This ensures that only one leading value can be applied to any given paragraph. Changing this setting does not affect the leading in existing frames. This may be a worthwhile "safety" feature, but strangely, it does not apply to paragraphs with Auto Leading applied. The problem with having this preference turned on is that when you apply optical leading, you need to apply more than one leading value within a paragraph.
Figure 4.15 The Apply Leading to entire paragraphs option keeps your leading within a paragraph consistent. However, it doesn't work with Auto Leading.
Auto Leading is useful when you're experimenting with type sizes, but when you decide upon the size, convert the leading value to an absolute number — even if it is the same as the Auto Leading value. Here's why you shouldn't use auto leading:
- Auto Leading is proportional to your type size — but specific to the biggest piece of type in the paragraph. This means that if you have one word larger than the rest of the paragraph, your leading value will be 120 percent of the largest word or character.
- Auto Leading doesn't give you the control that you need. Sure, if you're using 10-point type, Auto Leading is 12 points, a nice easy number to work with. However, if you're working with 11-point type, then your leading value is 13.2, which is difficult to calculate in multiples if you intend to work with a baseline grid.
- While Auto Leading works fine for body text, it can look terrible when applied to display type, which generally requires less leading.
Figure 4.16 The problem with Auto Leading: 120% of what exactly? Because one character (a space at the end of line 5) is larger than the rest of the paragraph, the leading is inconsistent.