Just a self-reminder - I used to know this but it had slipped out of the sieve of my memory - had to look it up again in The Pen and Ink Book (amazing and highly inspirational book, packed full of incredibly useful information that's hard to find in today's shallow sound-byte surfing world). Good to know - I almost decided to let last nights' ink drawings cure overnight before adding the charcoal wash. Finally I just said screw it and tried, and no smearing. I don't think they had waterproof ink in the Renaissance, did they? No wonder they always used big simple washes - it's when you work a wet area too much the ink threatens to smear and infect your wash. So simple bold washes is the way to go.
Also, just found this amazing page on a blog featuring Cambiaso drawings as well as some other great ones that are just as informative to an artist trying to learn figure drawing from the old masters. Ubaldo Gandalfi in particular is also fantastic!
Changed it from 30 minutes to an hour because I just got a little smearing (more like faint but noticeable blossoming on some of the thickest lines) after waiting at least a good 25 minutes. Don't want any more of that. Also, I want manilla paper and brown ink - I want to be Luca jr!