Is there any research with respect to how font-weight affects readability?

1. How does font affect readability?
2. Does font size affect reading comprehension?
3. Does font size affect reading speed?
4. Is bold font harder to read?

How does font affect readability?

Different types of typefaces (fonts) have different essential levels of readability. Spacing is also vital for text to be legible. It's beneficial for the reason that it helps the eye to find a block of font as a group, and also supports the reader quickly to find the beginning of each line.

Does font size affect reading comprehension?

Along similar lines with previous studies that have shown that decreasing font size impairs reading rate and accuracy in young children, in this study decreasing font size impaired comprehension.

Does font size affect reading speed?

Conclusion: This study shows that line width and typeface have little influence on reading speed in people with mild to moderate sight problems. Increasing the minimum recommended print size from 10 points to 14 or 16 points would significantly increase the proportion of the population able to read fluently.

Is bold font harder to read?

Bold text is less easy to read than regular text and its nature is not conveyed to screen reader users. Avoid using underline as a style. It is less easy to read and users expect underlined text to link to other content.