Cowanw, I use a mixture with equal amount of FO and palladium solution.According to Dick Arentz's book, the appropriate exposure time/distance can be dertermined this way by having two to three black wedges reach maximum black and indistinguishable from each other. I did experiment with decreased distances last night,1.8 inches, for example, and exposed for half an hour.Then I saw bleeding and several numbers got blurred.But still I didn't see any step reaching maximum black. As I'm planning to make palladium prints with digital negatives, I'd like to control the contrast of the negative to match the paper, rather than controlling the contrast of the solution.But I don't know now how to get that basic exposure time. Pity that I don't have NA2 on hand otherwise I'm eager to see what happens if the contrast changes. And how come my contrast obtained with a "normal" mixture of sensitizers are so different from others?

Loris, thanks much for the kind suggestion. And if the coated paper can reach maximum black in several minutes, may it prove that the FO is not so stale?