Diluting ziatype/PtPd/saltprint sensitizer

[ValoPeikko]

Today I tried a new batch of papers to me and found them to drink up way more sensitizer then any paper I've used before. They're washi type papers and I've seen lovely prints made on that kind of paper before. Just wondering if people dilute their sensitizer with distilled water, since considering the amount of sensitizer they drink up, it seems like it would cause issues by it self (specially in salt prints and ziatype, due to selfmasking). Or do I simply use more sensitizer and allow the paper to drink it up. This paper sucks the sensitizer so fast it's impossible to get even coating (even with out any tween20 or similar agent).

Never had this issue before, not with gampi or other papers. Not even with watercolour papers. With salt prints I can simply use more gelatin sizing, but with ziatype I don't think that's an option.

 

[DennyS]

I don't have any experience with washi, but I have found that I can dilute platinum chemistry with up to about 12% distilled water when coating soft paper. Any further dilution and the blacks start to weaken. You'll probably have to do some testing...

 

[nmp]

Just wondering if people dilute their sensitizer with distilled water, since considering the amount of sensitizer they drink up, it seems like it would cause issues by it self (specially in salt prints and ziatype, due to selfmasking). Or do I simply use more sensitizer and allow the paper to drink it up. This paper sucks the sensitizer so fast it's impossible to get even coating (even with out any tween20 or similar agent).

Never had this issue before, not with gampi or other papers. Not even with watercolour papers. With salt prints I can simply use more gelatin sizing, but with ziatype I don't think that's an option.

Wouldn't you want to go the other way and make more concentrated solution (increasing the viscosity) so there is less propensity for paper to drink up.

Also, I presume when you say you can use more gelatin sizing for salt prints, that is in the formula and not by the way of pre-treating the paper with gelatin solution. If that is true, can you not pre-treat the paper with appropriate gelatin solution to make it less porous for the subsequent steps, both for salt prints as well as ziatypes.

Just wondering.

 

[ValoPeikko]

For salt prints, paper can be easily gelatin sized before usage (but I prefer not to do that with washi paper as I don't like to do that on gampi paper either, due to difference in looks). But it can be done. Actually with bit of experimentation there's two routes to go for. One is changing my style of applying the sensitiser, not pouring it on paper at all, but taking it bit by bit from a vessel with a pre-wetted brush. One other option is to pre moisturise the paper so that it can't suck as much liquid while applying. Both can be used with dilution (which seems to be working nicely). These I came by from a facebook group thread (on alternative processes group) and with bit of trial and error on my part.

 

[pschwart]

For Ziatypes, try adding a drop or two of polyvinyl alcohol to retard absorption. Yes, adding distilled water to the drop count can be helpful with some papers, and lightly brushing the paper with a few drops of distilled water before sensitizing may help, too.

 

[nmp]

For salt prints, paper can be easily gelatin sized before usage (but I prefer not to do that with washi paper as I don't like to do that on gampi paper either, due to difference in looks). But it can be done. Actually with bit of experimentation there's two routes to go for. One is changing my style of applying the sensitiser, not pouring it on paper at all, but taking it bit by bit from a vessel with a pre-wetted brush. One other option is to pre moisturise the paper so that it can't suck as much liquid while applying. Both can be used with dilution (which seems to be working nicely). These I came by from a facebook group thread (on alternative processes group) and with bit of trial and error on my part.

Got it...

 

[nmp]

These I came by from a facebook group thread (on alternative processes group) and with bit of trial and error on my part.

You probably already saw this but this blog entry by Keith Schreiber talks specifically abut the Washi papers with links to some videos:

https://jkschreiber.wordpress.com/2016/04/09/notes-on-washi-for-ptpd-printing/