Hi Pete:
Glad you found our little photo-art oasis. Your post triggered me to do a little research on Chauve Auckenthaler, a husband and wife team. For the benefit of others, here are a couple links of interest:
Art.com - Example works
Art Select (1) - Another example
Art Select (2) - One more example...
Michaels.com - A little bio.
Regarding the specific end-to-end process details, the technique sounds facinating. Though I have no experience with watercolors nor watercolor paper personally, I wouldn't be surprised if some of folks who visit this forum have some comments/observations.
I'll be looking forward to seeing how this thread develops.
Thanks for checking us out and dipping your toe into the pool!
~DannyR~