We press on. I didn't mention that I am using two apps to look at the fonts: Firefox 4 and LibreOffice Writer. That way I avoid unusual things due to just one type handling system (I hope). Later, I want to see the final selections in another browser, and on an e-ink device (nook).
I wanted to get Dejavu back in the running if I could, reconsider Droid Serif, and throw in a new contestant: Arvo, the first slab serif to be examined.
Remember Dejavu had a letter spacing problem (or Win7 had one with the font). To try to rehabilitate Dejavu, I ran the regular sans and serif fonts through the @fontface generator at FontSquirrel (http://www.fontsquirrel.com/fontface/generator
) to see what would happen. It includes an auto-hinting option for better display in Windows, so I used that option to try to solve my issue.
I installed the new versions of Dejavu and the downloaded Arvo and Droid Serif. I didn't think such a simple thing as auto-hinting would work on the Dejavu fonts, but it did! Both the sans and serif fonts displayed none of the issues I saw earlier. I haven't confirmed that the other variants (italic, bold, etc) of Dejavu will be improved for Windows use by autohinting, but I am very encouraged.
Both Arvo and Droid Serif are legible at 6 pt (Arvo less so than the others), and have no significant problems with my simple color and spacing test paragraphs. Arvo looks light at these small sizes - it may be more intended as a display font.
The FontSquirrel @fontface generator also lets you subset the font's character set, so I can reduce font file size drastically (by 5x or more) by picking the Unicode ranges or languages I want to keep. So that problem is also solved.
Eight body text choices, five serif and three sans, are more than enough. For setting sans and serif fonts in the same book, it is nice to have pairs that work well together. It's clear that both the Droid and PT families were designed to do just that; that leaves the Liberation and Dejavu families and Arvo to check. I used a small book chapter, again in html and LibreOffice, to do the compatibility tests.
As expected, Droid Sans and Serif, and PT Sans and Serif, look great together. I have much more mixed feelings about both Liberation and Dejavu. Liberation is a metric-compatible substitution for Times New Roman and Arial, and I was not fond of using those two together over twenty years ago, and I'm still not today. The two families have the same general problem: the sans and the serif fonts don't match, and they also aren't distinctly, consistently different. There is some confusion at the individual glyph level. So I'm not sure what to do there.
PT Sans and Arvo don't look too bad together. But I'm not convinced Arvo is up to the task on its own. Looking at more samples will help, and maybe running it through FontSquirrel. I'dl ike to have a good slab serif as a option.
With the help of Fontforge, and spelunking in Constantia, I have come a long way in adding small caps, numeric subscripts, numeric and lower case superscripts, numerators and denominators, and text ("old style") figures to the two regular Dejavu fonts. Fontforge does everything but the old style figures automagically.
The text figures take more manual work. But it is pretty simple: copy the standard monospaced titling figures to a new location in the font and rename them ("nine.oldstyle"). Then there is a tradition for what to do with each digit. The 6 and 8 remain unchanged. The 0, 1, and 2 get squished down to the height of the lower case letters. The 3, 4, 5, 7, and 9 get dropped down (not squished) to match the height of the lower case - their bottoms hang below the baseline. Last, reset the widths so the numbers are proportional width, not monospace (the "1" gets the biggest change). Set up an Opentype table tagged "onum" to point to them, and, in theory, you are done.
So I'm pretty sure I can meet my requirements with at least three families: Droid, PT, and Dejavu. I'm not sure Liberation adds anything extra to those three, so it's optional. And I'd like to keep Arvo, or another slab around.
Since most ePubs don't require anything larger than 16pt, or at most 20pt, I see little reason to spend much time on display fonts. They barely begin to show their character at those sizes.
Does anyone have any advice, suggestions, or requests while I am going about tailoring these fonts for e-books?