In today’s digital environment, it is tempting to assume that line spacing (also called leading) settings will take care of themselves, given the convenience of the auto leading values that most software defaults to. While this can occasionally work for text, in the case of display type it is not only unwise, but typographically reckless, to overlook these settings. Display settings require considerable attention to detail in order to achieve professional results.
When choosing the line spacing of a block of display type, the overall goal is to provide enough space between lines to maintain good typographic color, texture, and optimum readability, yet not so much that the block doesn’t read as a cohesive unit. (A) There is no shortcut or formula for making this determination, as the optimal line spacing can vary from setting to setting. The major factors affecting line spacing are typestyle, type size, case (caps or u&lc), as well as the height and frequency of the ascenders and descenders. For this reason, line spacing for display settings is best determined on a case-by-case basis. (B)
One of the aims of balanced display line spacing is to achieve optically even spacing between the lines. This might seem guaranteed if they are all set at the same leading value. But this is a false assumption, as numerically consistent line spacing isn't always optically even. The following factors affect the appearance of line spacing in display settings of three lines or more:
- All cap lines mixed with u&lc. When this occurs, the line spacing above an all cap line (or a line with many all cap words) will appear to be smaller than the rest of the line spaces due to the caps ‘ invading’ the headroom above it. (C)
- Varying frequency of ascenders and descenders. When the space between a pair of lines must accommodate many ascenders and descenders, it will appear to have less line spacing than lines with fewer. (D)
The solution is to manually adjust the leading as necessary to create the appearance of optically even line spacing, even if the numbers vary greatly. Do not entrust these visual decisions to your software. And, finally, it’s advisable to print out the type, or to view it at high resolution, at 100% when making these determinations, as visual proportions optically change with scale and resolution.