Vince Lupo
Barely Known
Plain old glossy white paint does it. And if 'over a large area' you mean something like 8"x10", 5 - 18" lights separated by about 3" each would be fine. Printing with the sun will also work in a pinch, but it's not the most reliable of light sources, and as a previous poster mentioned, exposures even in bright sun can take upwards of two hours. Might not be so bad if you were printing a bunch of stuff at one time, and were relatively certain about the exposure times on all the negs (and I guess if you had time on your hands and only wanted to print during the daytime hours). But here again, this has just been my personal experience, and like everything else, we each develop the methods that work best for us.
One thing to keep in mind is that if you want to print larger than 8"x10" (like say an 11"x14"), you have to hand-coat that surface. That is a lot of area to cover, even with a 'puddle-pusher' (as I now remember those glass rod things were affectionately called). Plus you have to be fairly quick about it, otherwise some of the liquid might settle into one spot, and you get a splotchy coating. Coating an 8"x10" piece of paper definitely takes some practice, and the more texture a paper has, the more liquid required, and the quicker you have to be. That's one reason why I liked the Crane's Kid Finish, because it was relatively smooth, cheap, but also had a nice look to it.