Background: Tune Your Text to Improve Readability

To improve reading performance, individuals need the ability to “Tune their Text” or change how words appear on the screen using a full set of “Readability Features.” These include character shape (base font determines character shape and also weight; additional features can provide width expansion of characters), size (the size of the characters), spacing (inter-character space and line space) and background color (black on white, or white on black). The result is reading faster with greater ease and accuracy, therefore allowing for enhanced comprehension.

Readability Matters continues to look for insights that may suggest new ways to improve readability.


2015, the Initial Observation

In 2015, Readability Matters tested a classroom of 20 students using material presented in Times New Roman (the control) and 4 alternate formats based on AvantGarde. (A summary of the test is included in Proof of Concept Results: Maximizing Individual Reading Performance with Scalable Tuned Text.) A simple observation caused us to think about character spacing differently.


  • 95% read better with a clean round font
  • Additional Readability Features, including added character spacing and character expansion, improved reading proficiency for 40% of the students
  • The clean round font was the only change required for 55% of the students to achieve their best reading

Interestingly, the clean round font used in this study was an old version of AvantGarde. The font designers used very tight character spacing in this version of AvantGarde.

Notice the difference in perceived character spacing in Times New Roman and in this version of AvantGarde. This attribute caught our attention and raised the following questions. Could some readers be helped by reducing character spacing, as some are helped by adding it? (Microsoft offers an option to add significant character spacing in Immersive Reader, a feature that benefits many.) In the font families that have larger inherent character spacing, could another set of readers benefit from reducing it?


2019, University Students Agree

In 2019, Readability Matters conducted a quick survey of reading format preference. Thirty-seven university students aged 18-21 elected to participate. They were invited to play in the Readability Matters’ Sandbox and to design a format they would like to use to read.

There was an overwhelming preference to personalize text format; 36 of 37 students changed at least one Readability Feature. After making different base font selections (see options pictured), 30% of the students chose the “narrow” setting, which reduced the character spacing.

This survey reports reader preference for format; it does not measure reader performance. The results provide direction for further study. What is the relationship between reading format preference and reading performance? Consider the possibility that the preferred format is different from the best format. If the reader enjoys the reading experience and reads longer, does the preferred format deliver more value?


Next Steps

Similar to the 3rd-grade study, a segment of the university students preferred tight character spacing. As we consider implementation recommendations, tech, edtech and publishing providers should anticipate the need for less in addition to more character spacing.

Since 2015, Readability Matters has called for further study of character spacing and other Readability Features to support implementation recommendations. Some character spacing questions still to be answered are:

  • What is the range of useful character spacing settings? (Include decreased to increased character spacing text formats, in many styles of fonts)
  • What is the relationship between character shape (in this case, roundness) and reader need for additional character spacing?
  • As character spacing goes up, can text size go down?
  • Does the font’s inherent character spacing, weight or roundness predict a reader’s need for more character spacing?