Handcoated platinum printing out papers are nothing new. Pizzighelli describes several methods in Lietze's 1888 book "Modern Heliographic Methods" and Mike Ware described his method in the British Journal of Photography, Vol. 133(No 42), pp1190-1194 (17 October 1986), or 'An Investigation of Platinum and Palladium Printing', Journal of Photographic Science, Vol. 34, pp13-25 1986.
These methods rely on a simple system of incorporating moisture in the emulsion and paper to facilitate the developing out of the platinum salts during exposure.
Pizzighelli's method uses sodium ferric oxalate or ammonium ferric oxalate instead of ferric oxalate because of it's hygroscopic nature, chemically absorbing moisture.
Ware's method improved on Pizzighelli's with the use of ammonium chloroplatinite for the standard potassium chloroplatinite in order to achieve higher solubility.
As Ware states "the photoproduct from ammonium ferric oxalate is not an insoluble ferrous oxalate but a soluble oxalato complex of iron II, hence the printing out effect".
Tests that I have performed confirm that a water is of some form is essential for any degree of success. With the Ziatype lithium version, the moisture comes from its hygroscopic nature. With the cesium brown version, it is suspected that there a high percentage of water bound into the double salt of palladium and cesium. Humidifying a traditional ferric oxalate paper and printing it will result in a stronger print out image, but it will not be permanent enough to withstand water development and will typically appear quite grainy.
The Bostick & Sullivan Ziatypei i system, like the Pizzighelli and Ware methods makes use of hygroscopic ii chemistry and ammonium ferric oxalate as key to its printing out capability. In the Ziatype lithium chloropalladite and ferric ammonium oxalate are used.
When exploring the use of other palladium chloride compounds in the photographic process I came across a note which stated that lithium chloride was perhaps the most hygroscopic material known. I then surmised that its palladium salt would also display similar traits.
Lithium chloropalladite is a rare compound and is not listed in any of the common chemical references. Since palladium makes double salts with most of the alkali metal chlorides, I calculated its formula as 1.4 gms of lithium chloride to 2.3 gms of palladium chloride. Even though it is rare, our lab can produce it at prices competitive with the traditional sodium palladium salt.
To be on the safe side I used 1.7 gms of lithium chloride as the slight amount of extra lithium chloride should have no deleterious effect while any free palladium chloride might. Lithium chloride is a fairly benign chemical, and has been used in drugs for treating depression. I understand that it has no narcotic effect or 'high' for non depressives.
My first experiment making prints used the standard ferric oxalate solution and lithium chloropalladite. I made up the emulsion, and coated then dried the paper in the normal manner. I then steamed the coated print over a inexpensive sickroom humidifier vaporizer. The results were somewhat promising.
A very strong print out image was produced, but the contrast was very high, a great deal of graininess was produced, and the image darkened considerably when washed in the water. After several prints I noticed that the darkening was increasing with each print.
I suspect that this was due to the small quantity of EDTA tetrasodium that we add to our standard ferric oxalate solution. EDTA tetrasodium has a developing effect on any platinum print. I switched to an EDTA-free ferric oxalate solution and the darkening went away, but the prints remained grainy and contrasty.
My next experiment was to follow Pizzighelli's recommendations and use a 40% solution of ferric ammonium oxalate instead of ferric oxalate. I called this solution No 1. The print out image created was quite strong and no darkening was observed during development. The negative I chose was a little on the flat side and needed a boost in contrast.
I then made up a solution of ferric ammonium oxalate with some potassium chlorate, which I labeled No 2. In the manner of traditional platinum printing I mixed a portion of Numbers 1 and 2. The first print I made used a 50-50 mix of solutions Nos. 1 and 2, and the contrast was perfect for the negative I used which was a little flat.
The prints produced were neutral black, with a dead slate gray in the mid tones and hint of brown. They appeared very much like pure platinum prints.
After some fine tuning, I became excited as I was producing pure palladium prints with the beautiful gray and black tones of a classical platinum print. Frederick Evans could have not done better! Well at least in the color area. I don't propose that my negatives are in the same league with his.
Warm tones with Cesium
As the Ziatype was being tested by some of our better printers, the one thing that many wanted was the ability to produce warm toned prints.
My first experiments were to try the traditional platinum printers warm up chemical, mercuric chloride. Replacing part of the lithium palladium salt with mercuric chloride does impart a slight warmth to the image, but we have to deal with a highly poisonous chemical and we also have the added problem of how to dispose of it safely.
After a Thomas Edison like scientific quest that found me dumping all sorts of chemicals into the emulsion, none of which produced any warmth in the image, and many which produced useless lumpy precipitates, I decided to go back to the alkali double salts of palladium. Lithium is at the top of the periodic table and is the third lightest element next to hydrogen and helium. It's really a gas masquerading as a metal. I figured that if a light element produced cold tones a heavy one might produce warm tones, so I scanned down the left side of the chart and at the bottom of the alkalis is francium of which my Merck Index says is produced by the bombardment of thorium with protons, is exceedingly rare and very expensive. Scratch that! Next element up is cesium, and Merck says that the chloride is highly deliquescent, thus a good chance the palladium salt will be also, and not too expensive at a buck or so a gram.
It works. Cesium chloropalladite produces a lush warm tone print when used in the printing out Zia system. Remarkably, however, it does it in quite a different manner than lithium chloropalladite. The cesium palladium salt makes images while dry, no steaming is necessary, and in fact, if steamed it will produce cold tones. The lithium palladium salt will not produce anything other than a blotchy blur if exposed dry.
Many people associate cesium with the atomic clock at the National Bureau of Standards in Washington D.C.. That clock runs on a radioactive isotope of cesium. Many normally non radioactive elements have radioactive isotopes and cesium is one of them. The cesium salt we use in non radioactive and in fact, the teeny tiny portion of the hot stuff is removed before it ever gets to us.
The downside of using cesium is that at the concentrations necessary, it must be warmed up or kept warm to keep it in solution otherwise a chunk of undissolved salts will remain in the bottom of the container rendering the solution too week for good prints.
Warm tones with Tungsten
The cesium palladium process had some drawbacks" it solarized, and it needed to be kept warm to keep it in solution, I continued my quest for simpler system to produce brown Ziatype prints. After some intensive experimentation. I tried sodium tungstate as an additive. It worked! Finally an easy way to control the amount of brown color to the Ziatype print. The color is attractive and runs from a hint of brown to full sepia depending on how much of the tungsten salt is added. Sodium tungstate is a relative harmless chemical, the Merck Index says that lethal dose for guinea pigs is 990 mg/kg.
Roughly translated you would need approximately 70 grams to be lethal in a 160 lb. man. I had judiciously avoided experiments with mercury, due to its high toxicity and disposal problems.
I feel that the tungsten method is the method choice, however I am going to leave the cesium formulas in this document as there are those who may wish to experiment with it. Who knows, it may lead to other avenues of platinum printing.
Blue and purple tones with gold
One of the most interesting aspects of the Ziatype system is that a portion or almost all of the lithium chloropalladite can be substituted with gold chloride. My tests with other double salts of palladium show that invariably the gold reduces out and stains the highlights of the print. Lithium chloropalladite seems to have a unique property of not reducing out the gold.
The color shift varies from slightly warmish prints with purplish brown overtones to full lavender purple prints. My experiments have shown that up to 80% of lithium chloropalladite solution can be replaced with drops of 5% gold chloride.
Replacing all of the lithium chloropalladite with gold requires a double strength ferric ammonium oxalate and 10% gold chloride. My suspicions are that a small quantity of palladium is needed to strengthen the effects of the gold. There is little difference in color or contrast between a 5 x 7 print made with 7 drops of 5% gold chloride and a print made with 8 drops of 10% gold chloride.
Perhaps it is only a semantic argument that one print could be said to be pure gold, while the other is only 80% gold and 20% palladium.
The addition of gold, however, increases contrast considerably, especially at higher percentages. As information is obtained from workers in the field, we'll pass it on it future Ziatype instructions.
After exposure and before washing/ clearing, re-steaming the print will usually intensify the image. The intensification can be observed while the steaming takes place.
After exposure steaming deepens the blacks, and raises the contrast of the image. Prints with higher percentage of gold show more response to the steaming, even to the point of becoming harsh and gritty.
I suspect that using a more subtle humidity arrangement than the vaporizer spout might prove to give more control over this phenomena.
With a straight palladium Ziatype, if there is some drying during exposure, steaming will also complete any print out effect lost due to drying.
Printing Out and Self Masking
Since the Ziatype print is developing as it exposes the print will exhibit what is called "self masking." The first values to show are the lower "shadow values," Since the print darkens as it exposes, it will mask further developing out in those values. As the exposure continues, higher values will darken and this darkening will mask further developing out in those values as well.
In a "normal" developing out print, overexposure will push the low values out on the toe of the curve, resulting in "crushed" shadow values. One can think of the values on the curve as sort of a train, pushing on one end will push the values equally down the curve. In the Ziatype or POP one can think of the values as an accordion, as exposure continues, the lower values more or less stay fixed and the upper ones move down.
Traditional POP paper only came in one paper grade mostly due to its self masking property. One grade of paper could handle a wide range of negative contrasts. Contrast is controlled to a large degree by exposure.
Reports from the field are indicating that any exposure less than 2 1/2 minutes in a UV fluorescent light bank is probably too short even if the overall exposure is good there may be some crushing of the midtone values. In this case add more No. 2. ammonium ferric oxalate or a drop or two of a 8% potassium chlorate solution. This will boost the contrast, which you can then reduce by increasing the length of exposure. This technique can be used to expand the middle values. Since the Ziatype black can take large amounts of No. 2 or "chlorate boost" without graining up, this can be a valuable technique, however, printing times can increase at an alarming rate.
This system has another remarkable property in that it will work as a traditional developing out system as well as a printing out system.
Standard developers such as potassium oxalate or ammonium citrate produce light airy sepia prints. Using a Cold Bath developer will produces a rich black-brown print, similar to a ferric oxalate and sodium palladium print, but with a bit more warmth.
A great deal of image control can be gained by mixing the printing out and developing out aspects of the Ziatype.
A slight humidity-steaming, which will produce some image during exposure and then developing the print in Cold Bath or other developer can produce tones in between cold black and sepia. If done with skill or if a little serendipity joins you, split tones can be produced.
I produced some interesting split tones with gold and palladium; the shadows being brown-black, the mid-tones and highlights moving to lavender-purple.
Pure Ziatype is highly predictable and controllable. Playing in the area of mixed modes (POP- developing out) and split tones can be maddening and is not for the faint of heart. Those who venture into this area should be more a student of John Cage and less of Ansel Adams. There can be sheer delight in producing a gorgeous split toned print, followed by the agony of not being able to do it again.
MAKING ZIATYPE PRINTS
|Solution No. 1||ferric ammonium oxalate||10.0 gm|
|Solution No. 2||ferric ammonium oxalate||10.0 gm|
|potassium chlorate||2.0 gm|
|Solution No. 3
|palladium chloride||2.3 gm|
|lithium chloride||1.7 gm|
|Solution No. 4
Warm tone additive:
|sodium tungstate||4.0 gm|
| This solution may be diluted for smaller prints.
1 drop of this concentration will produce
quite a bit of warmth in an 8x10 print.
|Solution No. 5
Contrast boost - 8%:
|potassium chlorate||2.0 gm|
|Solution No. 6
For gray/blue/purple tones
|gold chloride||5% solution|
|*||sodium sulfite||15 gm|
|*||citric acid||15 gm|
|*||Kodak Hypoclear||25 ml|
|*||EDTA tetra-sodium||15 gm|
Clearing and Washing
Rinse in plain tap water. It will clear in about 1 minute.
Follow with a 5 minute wash.
Some papers may show some yellow staining due to not clearing sufficiently, if this happens use sodium sulfite or Kodak Hypoclear or equivalent to remove the stain and then follow with a 5 minute wash.
The ratio of the coating solutions is the same as in normal palladium printing. The total drops of ammonium ferric solution will equal the number of drops of lithium chloropalladite or cesium chloropalladite.
Vary the portion of No 1 and No 2 to obtain the contrast level needed. Use more No 1 for lower contrast prints, more No 2 for higher contrast prints. The Ziatype process will handle a print with high levels of No 2 with no visible increase in graininess.
Use the lithium chloropalladite for cold tones , for warm tones add 1 or more drops of sodium tungstate Solution No. 4.
For a 5 x 7 print with a mid level of contrast, a good starting point would be 4 drops of Solution No 1, 4 drops of Solution No 2, and 8 drops of Solution No 3. Remember that the total of Nos. 1 and 2 should equal the No 3, and the No 3 can be a mix of a, b or c.
* If more contrast is needed, use one or more drops of Solution No. 5, the 8% contrast boost. A half strength can be made and used as well.
* I prefer to coat with a glass rod, though a brush will work. The trick is to get enough, but not too much emulsion on your paper. When coating a 5 x 7 print with a glass rod I've found that 3 or 4 slow swipes across the print is enough. The last swipe pulls any excess emulsion to the edge of the print or off the paper entirely iii.
* Dry with a hairdryer or use the method you've been drying your standard platinum palladium prints .
Hold the print over the spout with the emulsion side facing the spout and move the print around to steam the paper evenly.
(At first I used an inexpensive Sunbeam Model 300 steam humidifier purchased at a drugstore for $9.00. It worked but had a tendency to spit. Other Ziatype workers have reported better results with the electrostatic vaporizers.
The Sunbeam versions of these cost in the $40.00 range I have not been extremely careful, and my results have been good. The emulsion seems to readily absorb the moisture. I humidify a 5 x 7 print for about 30 seconds.)
* Quickly place the print in a print frame and place a piece of acetate or acrylic between the frame back and the paper to retain the print moisture. This can be any plastic sheeting and is best if the size fits the frame fully. Also a Mylar negative sleeve can be used, just place the coated paper in the sleeve and in this way, both the negative can be preserved and humidity can be maintained..
* Expose the print either in the sun or with a UV light source. Within a minute or two in the sun, or several minutes under artificial light you will see the margins darken. In a few minutes more the margins will darken to a dark purple black.
(You may want to use a piece of 1 mil Mylar or acetate between the negative and the paper to prevent any damage to the negative.)
* A standard print frame is recommended as this allows you to check the progress of the printing out. When the print appears as full and complete, you are finished printing.
(A moist paper towel placed between the acrylic dam and the back of the print frame helps retain moisture during exposure though it is usually not necessary. The order: frame glass, negative, Ziatype coated paper, plastic dam, damp paper towel, back of print frame.)
* Immerse the print in water and wash for 5 minutes. With some papers there may be a yellow tint left in the paper. In this case clear for 5 minutes in Kodak Hypo clear or equivalent, or sodium sulfite, or any other platinum clearing agent, then rewash for 5 minutes.
* Blot and complete drying on a screen.
* Sell for money, give to friends, or keep in a secret box under your bed to be privately enjoyed when you're feeling down.
For a color shift to the burgundy and lavender shades, substitute gold chloride (3c) for the lithium palladium chloride(3a). Gold chloride can
1 drop out of 8 will only give a slight burgundy shift, 7 drops out of 8 will give a bright purple print. It is difficult to substitute all of the gold as a small quantity of lithium palladium chloride is needed to maintain density if gold is used.
Brown tones with cesium chloropalladite
Use cesium chloropalladite (3b) instead of the lithium chloropalladite. Do not steam after drying. It will produce a strong print out image and will be several stops slower than the lithium version. After exposing a dry cesium print, the print can be steamed before placing in the water bath.
This will reduce contrast and bring up the underexposed highlights. A print placed directly into the water bath may undergo a slight increase in development over the printing out image. If it is desired to prevent this increase in image density, use a first water bath of 5 grams of potassium dichromate to a liter of water. This may also increase the contrast of the print slightly.
The cesium chloride will need to be warmed before using as at its concentration, it will crystallize out at room temperature. Temperature should be 90 to 120 deg. It is not critical as a few crystals in the bottom will not hurt and if too warm, it will cool off when mixed with the ferric ammonium oxalate anyway.
The Ziatype cesium brown will not tolerate the large amounts of No. 2 or chlorate boost and the black will. It is more prone to graining up with large amounts of No. 2.
So far the use of gold in a print with cesium chloropalladite is problematical in that the gold tends to reduce out and stains the prints highlights.
A lithium coated print that is fully steamed before exposure and the humidity being preserved during exposure by the use of a plastic dam between the frame back and the print will produce a neutral black image with pure palladium. If the paper is slightly dried before exposure, the resulting print will have a brown cast to it.
The print out image will not be as strong as a fully steamed print but if re-steaming is done after exposure the print will darken. A Ziatype palladium print that is dried and not steamed before exposure will give little or no printout image. It will develop out fully with steaming after exposure and will be sepia in color.
If Cold Bath Developer is used the print will be a rich brown-black. Most other standard pd/pt developers will produce brown to sepia images.
Small quantities of the traditional potassium chloroplatinite can be added to the Ziatype in substitution of the lithium palladium chloride. We recommend that no more than 25% of your lithium palladium solution be substituted with platinum.
The addition of platinum will boost midtone contrast which can get crushed somewhat when printing long scale negatives.
Ammonium chloroplatinite can be used alone or in conjunction with the lithium palladium chloride.
Benefits of the Ziatype System:
* Print by inspection, what you see is what you get. The print fully develops in the light as you expose it.
* A choice of a traditional timed developing out system with the same chemistry.
* No solarization even with pure palladium.
* The benefits of a self masking printing system.
* Color controls with palladium from charcoal black, to sepia. With gold and palladium, from burgundy, to raging purple with no highlight staining.
* No developer and usually no clearing agent is needed.
* Better contrast control with less graining using No. 2 than with developing out systems.
* Better paper tolerance, it's not as picky about the paper it's on.
* Printing speeds increased by as much as two stops in many cases.
I have been using Cranes Platinotype, Cranes Parchmont Wove, and Cranes Kid Finish AS8111 paper with good results.
Many of these tests were performed in Santa Fe, New Mexico, elevation 7000 feet (2200 meters). Temperature was near 80^F (25^C) and the humidity was below 20 percent . If it works here it should work most anywhere.
Since both Lithium chloropalladite and cesium chloropalladite are very rare compounds and are not in general use in industry, there is no available toxicity data. However groups of compounds usually share similar toxic characteristics. For instance mercury compounds, if water soluble, are all poisonous, as are most cyanides. The lethal dose for cesium chloride is listed as 1.5 g per kilogram in mice and lithium chloride as 1.06 gram per kilogram in mice.
This roughly translates into 50-75 grams for a lethal dose in a 150 lb human. The are only modestly poisonous. Palladium chloride is 18 mg (thousands of a gram) per kilogram in rabbits as a lethal dose. We can extrapolate that the cesium and lithium versions of the palladium salts are only very slightly more poisonous than the sodium tetrachloropalladite in common usage in palladium printing.
Bostick & Sullivan will be happy to recycle any leftover quantities of platinum or palladium salts. For small quantities , dilute with several volumes of water and soak a piece of steel wool in it overnight. The steel wool will become plated with the platinum or palladium metal from the solution leaving the harmless chloride behind. There should be some dark sludge which will be harmless iron compounds.
The steel wool can be safely disposed of and the chloride should be sewer disposable, though you should check any local ordinances, especially if you are on a cesspool.
This method can be used to remove any platinum or palladium from developer solutions.
Powdered zinc can also be used in place of the steel wool.
Most problems reported seem to be caused by using too much sensitizer as mentioned in footnote 1
i. Named for the ancient Southwest Anasazi symbol for the sun, familiar as the circular image with 4 sets of 4 rays seen on the flag of New Mexico and its license plates. It seemed appropriate as we have just moved to New Mexico and I have been using its sun to make the prints
ii. Hygroscopic: readily absorbing moisture, as from the atmosphere
iii. Too much coating will cause grain and splotchiness in the print, This is due to the printing out nature of the process. The printed out portion will mask any sensitizer underneath the exposed layer, and if tiny particles of the top layer flake off, the bottom layer will not be exposed and show as white grain. There is no gain in dMax obtained by heavy coating.
Ziatype Images provided by Dick Sullivan
The urban landscape is called "The Cornfield". That's the historic name for the area where the tracks are. It's by Richard Sullivan c. 1982. It's of the LA skyline. It's a Lithium Palladium Ziatype with some gold.
This image is from a c. 1905 glass plate 4 x 5 negative by Harry Smith, a Danish American photographer active in San Francisco at the turn of the century. It's called "The Cook Tent". It's a 100% Cesium Palladium Ziatype.
Please send comments to Richard Sullivan at firstname.lastname@example.org.