New research actually finds that heavy typeface doesn’t help people retain material. Instead, researchers find that unusual or difficult to read fonts actually help increase the likelihood that you will remember what you read.
A study published in the journal Cognition found that trial participants who studied material in the familiar and easy to read 16-point Arial font only retained about 73% of the facts when tested later. The rest of the group that read the material in 12-point Comic Sans MS or 12-point Bodoni MT remembered 85.5% of the things they read.
As quoted in the source for the post, The New York Times, study co-author Daniel M. Oppenheimer says, “The reason that the unusual fonts are effective is that it causes us to think more deeply about the material. But we are capable of thinking deeply without being subjected to unusual fonts. Think of it this way, you can’t skim material in a hard to read font, so putting text in a hard-to-read font will force you to read more carefully.”
But, it is important to note that reading fonts that are too small can actually increase your blood pressure and can lead to eye strain. If you want to start experimenting with unusual typeface to increase your powers of retention, do not do so at the expense of your eye health.