Since I removed the painting tutorial, done seven years ago, from my website, I have constantly been getting questions about it. To be honest I've long become quite embarrassed about it. It's old, outdated, and plain ugly. But I did do a new tutorial 8-9 months ago for a magazine called Imagine FX which they have subsequently posted, in its entirety, on their website. So for all of you who've been asking, forget the old junk, this is the new stuff:
http://www.imaginefx.com/-2287754330544769555/Combining_traditional_and_digital.html