As an example of the way my thinking about this project has evolved, this is the first title page from the end of December, last year:
Based on a Beatus from a psalter in the Morgan Library, 6 3/8" x 10".
And the same page, redone last month and finished on June 19:
Based on a Beatus from the Hunterian Psalter, 7 1/2" x 11".
They are both inked and painted on Text Wove paper, but the second version (really the fourth, I think, but we don't need to talk about the missteps) is on a larger piece that has been dyed with tea, because after looking all these months at pictures of parchment manuscript pages, the plain paper looked just too white.
After completing drafts of about 10 pages, and about the time (February?) that I bought a wide-format printer, I decided I didn't need to restrict myself to the page size dictated by how many pages I could cut from a single sheet of paper, and could instead restrict myself to a page size dictated by HP. The printer would take up to 11" x 17" paper. I didn't want a standard letter-size page--too modern and familiar--so I settled on 7 1/2" x 11" pages and started redoing the earlier pieces.
Early in June I started dyeing the paper, first by dipping it in a tea bath. Then I tried a diluted walnut ink bath. Then spraying and brushing out. Walnut is more brown, tea more yellow. Spraying and brushing dries more quickly and the paper doesn't buckle as much. Trials and experiments. More pages to do again, more opportunity to change and improve.