Drop count for 4x5 Ziatype

[matt miller]

I'm going to make my first ziatype tomorrow. I'm going to start with a 4x5 neg. How many drops should I start with? I will be using cot320 & brush coating. The B&S kit instructions state 15 drops of ferric ammonium oxalate & an equal amount of lithium palladium for an 8x10. Will 4 drops of each be enough for a 4x5?

When I put these drops in a shot glass, do I have to mix them up with something, or just swish them around?

 

[colrehogan]

I have never used less than 6 each for a 4x5 Zia (mind you, it looks like I've coated for a 5x7 by the time I'm done). As I understand it, you need more solution for a brush. As for 8x10, I've tried 15, but found that 18 works better for me. I use a rod at the moment for coating, but have ordered some brushes.

Swirling the mixture in the shot glass is good enough.

 

[payral]

The answer depends according to the brush.
If you use the "magic brush" 4 drops of each (AFO & salt) will be OK, same for coating brush, with an other brush 6 or even 8 drops will be necessary.

Philippe

 

[payral]

One more thing, if you use COT-320 you need at least 50% RH, more the better.
The best way to use it is to prewet the paper at least 10 mn before coating.
For that I use two dishes, the bottom one with water, some floating material to keep the paper over and not in contact with water and the other one as cover.

 

[matt miller]

The humidity thing kind of has me worried. My hygrometer (I think that's what it's called?) in the basement darkroom has been reading around 38-42% lately. I've read about humidifying each sheet above a humidifier, but not about the trick with the two trays. Since I don't have a humidifier, I'll give that a try. I was planning to buy a humidifier tonight, but think I'll try that first. Thanks.

As far as drop count goes I think I'll go in the middle & start with 5 drops.

One more question. The B&S instructions say to add one or more drops of the sodium tungstate to warm the print. This is for 8x10. I want a warm tone. Is one drop of the 40% solution too much for an 8x10 or should I dilute it? Or should I just do it & see what I get?

Thanks for your help.

 

[matt miller]

By the way, I'm using a Richeson 9010 2" brush. This is the "magic brush" isn't it?

 

[payral]

Yes it is.
The best of the coating brush, all on the paper and nothing for the brush.

 

[colrehogan]

One more thing, if you use COT-320 you need at least 50% RH, more the better.
The best way to use it is to prewet the paper at least 10 mn before coating.
For that I use two dishes, the bottom one with water, some floating material to keep the paper over and not in contact with water and the other one as cover.

The humidity here has been in the 31-37% range for the last month, but I've used the humidifier to do some printing. I've been humidifying for about 1 min 40 seconds. I usually move the paper about 2-3 inches from the humidifier. Just make sure to let your paper dry after coating. You don't want to drag your gloved fingers across this paper to determine wetness; it's hard to describe what I've seen, but trust me you don't want to see it on your paper.

 

[waynecrider]

Hey Mark

The coating thing will come to you real fast. It doesn't take to long to know. I use the glass rod (puddle pusher) myself and find it very easy, and I can work with 7 drops total for a 4x5. Remember you can add drops of water to the solution to extend it enough to coat, and the water will essentially humidify the paper. You can also run a hot shower and steam a bathroom. The whole thing about Ziatype is consistency, and even then with sun exposures it's a guess. It's fun tho, but watch out; Next you'll be wanting to build a UV expsoure unit.

 

[donbga]

As far as drop count goes I think I'll go in the middle & start with 5 drops.

One more question. The B&S instructions say to add one or more drops of the sodium tungstate to warm the print. This is for 8x10. I want a warm tone. Is one drop of the 40% solution too much for an 8x10 or should I dilute it? Or should I just do it & see what I get?

Thanks for your help.

Use at least 7 drops for a 4x5 print when coating with a glass rod or Magic Brush with Cot 320 and other similar papers.

As you have noted humidity is important and if you can't hold at least 50% humidity in your coating area you will have some problems getting the POP to work properly. Always use a sheet of mylar behinf the paper in your printing frame and you may want a piece above the negative to preserve humidity inside the frame.

One drop of 40% solution of sodium tungstate for an 8x10 is fine you may want to use 2 drops. For a 4x5 print you will need to dilute the tungstate.

There are other ways you can get warm tones; one is to use cesium palladium solution and another is to use lithium palladium solution and allow the coated paper to dry out for several hours in the dark before exposing. Printing speed will be reduced using dryer paper. You can also develop the print in warm potassium oxalate to get a warmer print or brush develop with glycerin and potassium oxalate.

In short the ziatype (pop palladium) process is like a piece of plastic, after some practice you can print with feeling rather than working strictly by the numbers.

Good luck,

Don Bryant

 

[donbga]

By the way, I'm using a Richeson 9010 2" brush. This is the "magic brush" isn't it?

Yes.

Don Bryant

 

[matt miller]

Well, this weekend's ziatype printing went quite well. I started with some 4x5's. I started with 4 drops ammonium ferric oxalate, 1 drop 20% sodium tungstate, & 4 drops lithium palladium. This was more than plenty emulsion. I think I over brushed a couple of the prints because I'm seeing some white spots that look like surface abrasion or something. When do you stop brushing?

I used the two tray method that payral suggests to humidify the paper. I don't know how consistent it was, but it seemed to work ok. Does humidiy effect printing speed? I'm not sure I had enough. My exposures were around 7-10 minutes in my uv unit.

As far as warm tones go, I only made a few prints & did not get the prints as warm as I'd like. I will try some of donbga's suggestions.

It was a whole lot of fun though. I can see a new addiction forming.