I don't understand. The watermark in the corner is gray, but the actual content is already black. You can't get darker than black. What do you actually want to do?
Do you want it to use a thicker font? There's no way to do that short of converting the PDF to another reflowable format and then convert back. But you might as well just use calibre to convert to a reflowable format your reader can use and leave it at that.
Last edited by frabjous; 10-17-2010 at 10:30 AM.
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