Typography Principles That Make Text Actually Readable
Readable typography is not about picking a nice font. It is about a dozen decisions that work together. Here are the principles I rely on. Typography is the layer of design that readers interact with most, and it is also the layer where small mistakes compound. A font choice that is slightly wrong, a line height that is slightly off, a measure that is slightly too long. Each is minor alone. Together they make text uncomfortable to read, and readers cannot articulate why. They just leave. After years of refining my approach, here are the typography principles I rely on to make text actually readable. Set the Measure Between 45 and 75 Characters The measure is the length of a line of text. Too long and the reader loses their place when returning to the start of the next line. Too short and the rhythm of reading is broken by constant line breaks. The comfortable range, established over decades of print typography research, is 45 to 75 characters per line, including spaces. I set this with the ch unit, which corresponds to the width of the zero character in the current font. A max-width of 65ch lands most body text in the sweet spot. More guides are on the Spark Blog.