I've been using the formula for ammonium palladate in the Ware information on the Ware POP process. It's a little more concentrated than the normal formula, but my tests years ago appeared to indicate that the traditional formulas for FO and PD had a bit of an excess of FO anyway, so I figured it would work fully without waste.

His formula calls for 1.8 g NH4Cl and 3g PdCl in H2O to make 25ml.

The molecular weight of Nh4Cl is slightly less than NaCl, but ammonium chloride is hygroscopic, so while you could use essentially the same formula as the traditional sodium chloride, you really should be thinking about a bit more to adjust for the captured water.


Anyway, I like the color better, and it seems to solarize less, and it may have some hygroscopic properties that make it partially print out, which could be used to adjust image tone and contrast as well. I'm not doing that, but I believe an advanced user could use that to good effect.


---Michael