Chris,
I have one that gives 60% if I do the prints in their lab,
another where I get 50% of the profit (subtract cost of making and framing
the print from the retail cost and take 50% of that).
I think this second one is the fairest. Both are non-exclusiveand
open ended.

Roger

Thanks for the information! I'm more concerned about the duration of
exclusive access to the work than anything else. It seems excessive.