Trying Zerochrome-SbQ (PVA-SbQ)

[koraks]

Yeah, lots of white pigment - lots. 4x is a good starting point. Take it from there.

For orotones, I've so far always used gelatin with an easy-to-disperse 'gold' pigment, which really is mica (with maybe a little iron oxide?) with a truckload of dispersants added to it. Works surprisingly well. Make a gel with this pigment and then pour it like you'd pour a collodion wet plate. Again, it takes a lot of pigment to make a layer with sufficient covering power.

 

[PGum]

Consider an experiment with etched ( single side) “ frosted” glass. It might provide some extra holding for the highlights and with some “dithering” from the hills and valleys that may also help to extend that end.

 

[photo81]

Just a hello to the forum. I am very, very, very new to alt-processes and I'm working my way through all the informations I can get. I live here in Germany near the Alps and I consider me an amateur. I'm just interested in the least toxic processes with chemicals I can get her in Europe.

Just a question to this forum:

Is there a seller here in Europe where I can get the PVA-SbQ or the raw chemicals. And yes, I already stumbled across the Calvin Grear's site. And a very dumb question also: is printmakers friend the same as readymade PVA-SbQ?

Thank you for help!

 

[koraks]

Just a hello to the forum.

Hello to you too!

Is there a seller here in Europe where I can get the PVA-SbQ or the raw chemicals.

I'm not aware of it, no. You could always try and ask Kees Brandenburg (polychrome.nl)

is printmakers friend the same as readymade PVA-SbQ?

No, it's not exactly the same, but the concept is sort of similar.
Printmaker's friend is also low/non-toxic and as you've found, it's easily purchased in Europe as Calvin operates out of Spain. So I'd recommend starting there.

 

[AndrewBurns]

Yeah my advice would be to start with PMF now that it's available again. It's already mixed up for you and there's solid instructions online to help you with dialing in the process, which should give you the best chance of success.

The PVA-SbQ process is still kicking my rear-end, I've probably spent about half of my 1kg of raw PVA-SbQ concentrate and 6 months doing nothing but test prints at this stage, without ever having printed an actual photo (except for my experiments of PVA on glass).

Yesterday I tried what Calvin is currently recommending for PMF, which is mixing in some arrowroot powder and reducing the number of coats to 4. The arrowroot seems to make the hardened PVA much tougher during development, I was able to be much more aggressive during development (pouring water from 40cm high onto the print, spraying with a bottle etc.) and the pigment stayed on the page which wouldn't have been the case previously. Unfortunately I had to be that aggressive during development because the print wasn't clearing at all until before getting rough with it. Also there was a lot of staining and speckling, which I believe was caused by brushing on the top layers causing damage/mixing the previous layers. I've been using a fairly soft synthetic brush but I might try a hake brush again.

I'm also thinking I need to make my layers thicker to better resist the abrasion, particularly now that the addition of arrowroot seems to make the exposed PVA harder and so thicker layers are less likely to detach from the paper.

 

[PGum]

I'm just interested in the least toxic processes with chemicals I can get her in Europe.

Another option is diluted fish glue+ ferric ammonium citrate as sensitizer. Develop in dilute hydrogen peroxide (CHIBA process). Fish glue as bought is essentially 45% fish gelatin in water with preservatives and a small amount of TiO2 for opacifying. A few nice looking prints using this process have been posted here in photrio. Speed is relatively slow, like cyanotype but one can compensate somewhat with newer more intense UV LED sources. I should add too that the addition of starch powder will improve the layer adhesion as was mentioned by Calvin Grier for use with his PMF emulsion. I have used rice starch on occasion for this.

I have also worked with the low toxic PVA-SbQ, in a similar fashion to Kees’ and Simone’s zerochrome SbQ. I love the speed but not sold on it so far for various reasons. I won’t count it out for future use though. Calvin Grier’s PMF ( possibly SbQ-based) was already mentioned as an option.