We know that serif and sans serif can perform equally well, if you choose a body text size above 12 pixels. Below 12 pixels serifed typefaces don’t render sharply enough, but on desktop monitors 12 pixels, I personally think that is definitely too small anyway. So my question is: do you think we should ban 11 pixels font-size on any of our design? Serif or sans serif? Should I include that in my functional/specs requirements documents?
closed as not a real question by DA01, ChrisF, dnbrv, Charles Boyung, Ben Brocka♦ Jul 5 '12 at 19:40
It's difficult to tell what is being asked here. This question is ambiguous, vague, incomplete, overly broad, or rhetorical and cannot be reasonably answered in its current form. For help clarifying this question so that it can be reopened, see the FAQ.
There are too many variables to consider before you can reasonably ban a particular sized font in a design.
That doesn't mean you should start using
If you're designing for a billboard, you may have to ban fonts less than 3 meters so that observers can actually read it from a distance. If you're designing for an array of lightbulbs, your font-size might be restricted to 6px because that's all you've got.
Additionally, some fonts become blurrier than others at small font sizes. A font-size of 9px might be reasonable for one font where another can't go any smaller than 13px.
As I noted in the comments on the question, our own ux.stackexchange.com site uses a
This "pixel" question is not relevant because 11 pixels looks different for each font and legibility is also dependent on screen resolution and many more parameters.
For more on your question on the topic Serif VS. Sans-Serif: