I have no idea how to go about this. One of the PDF readers may allow such a scale to test a single page print until it achieves a readable size. Acrobat/Reader will only go to 1000%.

But I wouldn't ever design something like this in this way. I would decide what the acceptable text size is and create as many pages as it took to accomplish it. Well, no, I wouldn't. I would use a genealogy application (like my wife does). Sure saves a lot of manual grunt work. But if I felt I needed to do this, I would do it as I described.

Mike