I tend to think that Sparkplug9 is fairly readable. It’s black text on a white background, and the text size is not tiny.
Or so I thought.
Take a look at this screenshot of the Forbes website. I scrolled past the myriads of ads and assorted site chrome:
I know it’s a little small in the image, but you can click the image to get it full-size.
In my opinion, that’s almost the most-readable website I’ve ever visited. And that includes Jakob Nielsen’s useit.com, theoretically the poster-boy for usability and readability.
Hmmm … thinking I’ll need to increase the font size.
One thing it certainly does: increase reading speed and enjoyment.