An Observation on Fonts - Improving readability by using *bold* versions of fonts
I recently purchased a used Cybook Opus. While I was poking around on it, I noticed that the previous owner had apparently added some fonts to it. While I was trying the different fonts, I noticed that one, Apple Garamond, had excellent contrast, with thick, easily-read letters.
When I looked in the fonts folder and opened the TTF file, I realized that they had only added the bold version of the font, so the device was forced to default to that version.
So, I went and tried fonts that I had previously tested on my Kobo Touch, but had found unreadable. In the case of the Kobo, I simply took a bold version of a font, deleted the "-bold" part from the file name, and copied it over the normal default. (So basically, the normal and bold versions were exactly the same.)
I found that a LOT of fonts that I had previously discarded were now quite useful. In some cases, they look TOO chunky--Vollkorn being one such example--but many of them looked great.
So if you're using one of the many readers that allow you to load your own fonts, I would encourage some experimentation, to see what you come up with.