How does screen reading affect typographic choices?
Less and less.
The quintessential problem of digital typography has been how to make fonts look good not only on high-end publishing equipment, but also lower-resolution office laser printers and personal-computer screens.
After 30 years, the hardware differences between these devices have largely disappeared. Thus, with screens becoming more paper-like than ever, there’s decreasing need to make special accommodations for screen reading.
Regardless of whether it’s displayed on screen or printed, digital type works by scaling a glyph shape to a certain size and activating the pixels that are inside the shape. Thus, the quality of rendered digital type depends on two factors: the number of pixels available (aka
But more pixels aren’t always better. At the high end, all reading is constrained by the physiology of the human eye. The eye’s limit of perceivable detail is usually estimated to be 1–2 arcminutes. (An
Because it’s an angular measure, reading distance also affects perceived detail. For instance, my desktop monitor is about 24″ away, which means I can see about 143 dots per inch. But on a tablet or phone held at 12″, I can see twice that, or 286 dots per inch.
For the first 20 years of digital typography, computer screens barely improved, remaining in the range of 75 dots per inch. During that time, companies like Apple, Microsoft, and Adobe developed technologies that were meant to make digital fonts look better on screen. This project became more urgent with the advent of the web. Some of the best-known fonts emerging from these efforts were Microsoft’s Verdana, Georgia, and Calibri, all of which were heavily optimized for screen reading. At that point, it was true that certain fonts looked better on screen, and others looked better in print. These fonts became the starting point for those designing onscreen typography.
But since 2010, screen hardware has been making up for lost time. High-resolution screens first emerged in smartphones, then spread to tablets, laptops, and now desktops. For instance, my smartphone display has a resolution of 326 dots per inch, and my desktop monitors have a resolution of 185 dots per inch, both of which exceed the limits of human vision. (By the way, if you haven’t upgraded to a 4K desktop monitor, it’s well worth it.)
What does this mean for screen typography? For font choice, it means you should use whatever font you’d prefer on the printed page. Those traditional
As for page layout, most screens are smaller in height and width than the traditional 8.5″ × 11″ printed page. So if you’re certain that a document will only be read on screen, it could make sense to shrink the page margins and raise the point size to adjust for this difference. But if a document could also be printed—most court filings would fall into this category—then it’s best to stick with a print-optimized layout.