It’s been a busy day starting with the ziatype process! My setup for finding the basic exposure was to use solutions #1 (ammonium ferric chloride) and #3a (lithium palladium). I first picked four different papers to try with zia — these had all been performing well with cyanotype and vandyke, so my guess was that they would be good for ziatype too. But, as it happens, there was only one good enough to continue with testing…

The ziatype essentials: Tween 20 surfactant, the basic zia solutions, a shot glass for the sensitizer, and a synthetic Sterling brush from Bostick and Sullivan.

One of the paper stocks — Bockingford Watercolour — behaved oddly straight away; it was impossible to coat the sensitizer evenly on the paper — it remained blotchy and grainy. The rest of the papers looked OK at this stage.

Some differences between the papers could be seen even in the dimroom’s yellow light; for instance, the sample on the left (Bockinford Watercolour) was very grainy and uneven right after sensitizing.

Another problem was my clearing bath. Having done some platinum/palladium printing 12 – 15 years ago I have a good supply of EDTA, which is supposed to be good for clearing ziatypes too. Well, it’s old, but dry and good looking stuff, kept in tightly closed plastic containers, so it should work, or… ?

However, my EDTA refused to dissolve!? I don’t remember how I dissolved it back in the early days, I think there wasn’t anything special about it… just mix to water. Now my clearing bath looked milky and cloudy, and I have no idea if it worked or not — these tests were just exposures without a negative, so no whites there to judge the progress of clearing.

I changed the clearing bath to sodium sulfite for the rest of the day — worked just fine…

Cloudiness in the EDTA clearing bath.

My EDTA powder is kept in these plastic bottles. It is purchased from a Finnish supplier (not in the business any more), the yellow label is just my old remarks on the dilution.

Anyway, properly cleared or not, this was just a test to define the basic exposure (the best density with the shortest exposure time) for the material. The results: There was actually one paper that was superior to my eyes. That was Guarro Casas, our good old outperformer, excellent in about every process we have tried. In this selection I didn’t have Bergger COT320 or Arches Platine at hand; they used to be my favorites for platinum.

The papers to choose from; from left and in the order of superiority: Guarro Casas (white), Saunders Waterford, Somerset, Bockingford Watercolour.

I found my basic exposure to be around 1200 units on our Sack exposure unit. Next, I started working to find the correct printer’s ink load for good ziatype negatives. I first used Epson 3800, figuring I’d need the heavy ink load that it could provide. But I soon realized that I’m not going to need those super dense blocking inks here, so I switched to Epson 1800.

I came to the conclusion of using the Guarro paper; it’s very easy to coat evenly with a brush, the Dmax is good, and it clears easily (and nice texture too, although could be a bit smoother to my taste). Saunders could be another good paper, with its warmer base, but it’s uneven somehow, it seems to absorb the sensitizer in a very patchy way…

A close-up of Saunders Waterford — I suppose the unevenness comes from how the sensitizer penetrates the paper fibres… the paper surface itself is quite smooth.

Here in Guarro paper the tone irregularities are not in the paper fibers — the texture showing here comes from the light hitting the surface at an angle (I took the picture with a digicam).

I had my negative and the humid paper stuck together couple of times… no problem here with inkjet negs that can be printed again, but I did ruin one of my Stouffer step tablets 🙁

If there is a hazard to ruin your negative in contact with the wet paper, you can use a thin clear acetate film between the negative and paper. It can blur your prints a bit, they say, but in my tests today, I couldn’t see any naked eye difference in sharpness between the prints with and without an acetate interleaf… but that may just be me and my old eyes 😉

An image transferred to the protective film from humid ziatype paper during the exposure… the paper too wet, I guess…

All my prints today have been made from uncalibrated inkjet negatives… the only goals have been to find a proper inkjet density for the negative (to print as the paper white tone), to find a suitable paper for the process, and finally, to get to know something about the paper humidity and the wet process issues.

I was trying to get my negatives’ ink densities right, to be able to get just paper white with the negative max density. I came to the correct negative density in an empirical way, by changing the print settings and making small test prints with ChartThrob. I didn’t use the colorized negatives here, because the all inks UV density of the Epson 1800, with photo black ink, looked dense enough.

So, I let the ChartThrob script analyze and build the correction curve from my best print of the gray patches. The curve looks quite extreme to my eyes, but I guess you could expect something like this when viewing the gray charts printed uncorrected… the shadows are blocked and without much separation up to higher values, like 40 %, while the upper tones respond quite linearly.

The first correction curve for ziatype negatives.

The test print with the correction curve doesn’t look too bad now… I’ll make some small corrections and try to print some photographs soon.

A print from the corrected chart. Nice, neutral platinum-like tones.

Here’s a list of my settings and procedure for today:

  • Workroom conditions: rH 74 %, temperature 24° C /75.2° F
  • Negative: Inkjet (Epson 1800, all inks, photo black)
  • Correction curve: Analyzed and built by ChartThrob
  • Sensitizer: Sol. 1 (10 g ferric amm. ox. > 25 ml dist. water) 8 drops  + sol. 2 (2.3 g palladium chloride + 1.7 g lithium chloride > 25 ml dist. water) 8 drops + Tween 20 (1:3) 1 drop
  • Paper coating: With brush
  • Drying: Left on table for 10 min., blowing with hair dryer (cool) 2 min.
  • Exposure: Between acetate films, 1200 exp. units (Sack) (ca 3.8 min.)
  • Wet process: Wash 5 min., citric acid 1.5 % 5 min., sodium sulfite 1.5 % 5 min., wash 20 min.
  • Drying: Hair dryer (hot)