If you like Ziatype and can source ammonium tetrachloropalladite(II) - formula: (NH4)2[PdCl4], I strongly recommend that you try the actual print out Palladiotype process; Ware-Malde Palladiotype. I'm totally converted to it; it gives me much much stronger (= considerably darker / better dmax...) images!
The problem with Ziatype is that the stock palladium and iron solutions have quite weak concentrations (still, they give perfectly fine images...); OTOH, with Ware-Malde Palladiotype you can use up to 50% more palladium per given image area, and this translates to significantly better results - at least to me. (See the attached scan of two prints made on the same paper; one Ziatype, one Ware-Malde Palladiotype. The lighter upper part is the Ziatype, the darker and larger bottom part is the Ware-Malde Palladiotype...)
For clearing, I use Keith Schreiber's / Howard Efner's protocol, slightly modified: (all amounts per 2000ml solution)
1.First clear / rinse: (mix fresh for each print & discard after use)
- 1 dstspn. citric acid
3 minutes
2.Acid clear: (keep and use for multiple prints)
- 1 tbspn citric acid
- 2 tbspn Na4 EDTA
- 1 tbspn sodium sulfite
(Each added in the above order, one by one, after the previous one is completely dissolved...)
3 minutes
3. Alkali clear: (keep and use for multiple prints)
Same as 2, omitting citric acid
3 minutes
4. 20 minutes wash
Edit: And if you have trouble in dry days, you can add 1 drop glycerin per ml of coating solution - it will help considerably to retain moisture in the paper. (Makes the process much more consistent too, works for both Ziatype and Ware-Malde Palladiotype...)
Hope this helps,
Loris.