Platinum / Palladium Process
The ultimate photographic medium. Highly collectible. Considered to be the most archival process. An exceptionally luxurious and long tonal scale which is impregnated directly into the printmaking paper. It’s “skin” and “feel” and reflective qualities are simply unparalleled. Nothing quite like it (although Piezography is often thought of as Pt/Pd on steroids). And although a legend follows it around that it is technically difficult, it is actually surprisingly easy to control with the Piezography Digital Negative. With traditional negatives it is difficult to control. If you come to our Vermont workshops (private or group), we can get you making high standard prints within three days.
The process "in a nutshell" involves hand-coating special uncoated, printmaking papers with an emulsion of sensitized noble metals. The coated paper is quickly dried and exposed in contact with a negative using strong UV light. The development is nearly instant. The print is cleared and washed and dried.
The Noble Metals
Palladium and platinum when used together form a synergistic relationship. The majority of “platinum prints” made today are made mostly of palladium because it is smoother, warmer, and less expensive than platinum. Platinum is considerably cooler than platinum, but only a small percentage is required to benefit. Some expert practitioners use 50% platinum to palladium. The majority of practitioners use between 20-30% platinum to palladium. However, those who love warm prints use no platinum at all. Platinum adds contrast to the process but contrast can be controlled in digital imaging with great control with Piezography Digital Negative.
Platinum and palladium printing are surprisingly non-toxic and safe. The noble metals are noble because they resist chemical action, do not corrode, and are not easily attacked by acids. Because they are non-reactive they can not form anything not currently found in nature, and therefore pose no natural threat to humans. Any metals which end up down the sink pose no harm to the environment.
While Ferric oxalate and Potassium oxalate are both poisonous, they remain non-toxic. Digesting a large quantity of it will make you ill. Oxalates are also found in spinach and rhubarb leaves. Consuming too much of these vegetables is poisonous. You can stand in a field of acres and acres of spinach or rhubarb and not get ill. There is nothing toxic about either spinach nor rhubarb. Dumping oxalates down the drain do not pose a toxic threat of any kind to the environment. But, dipping your finger into the tray of Potassium oxalate developer with an unprotected cut will produce an infection because oxalates are anti-coagulants.
EDTA and potassium citrate and Hypoclear are non-toxic to the environment.
What does pose a threat to humans are the poisons associated with inhaling the dry chemicals: palladium chloride, potassium chloroplatinite, ferric oxalate, potassium oxalate, EDTA, and oxalic acid. As long as you take prudent care with handling the dry chemicals it will pose no threat to your system. Do not eat or drink in the darkroom. Wear gloves. Wear a mask when mixing chemicals. Use protective eye wear when working with UV. Be careful of paper cuts and or cutting yourself with razor blades.
If you are weary or cautious about handling the dried chemicals or making a mistake in their formulation, please consider purchasing palladium and platinum and ferric oxalate in solution from us. The metals have no shelf life. You can purchase fresh ferric oxalate every 60 days (90 days if it has been mixed right before your purchase.) If it has not been opened, it is possible for a tightly capped bottle of ferric oxalate to last up ten months, after which it must be used within 60 days of opening. We tend to mix ferric oxalate on demand for our customers so that it is fresh.
It is possible to work in low level lighting. What is essential is that all sources of UV radiation are eliminated. The sensitized metals are peculiarly sensitive to Ultraviolet light. LEDs and Incandescent are generally UV safe. Compact fluorescent lights emit UV radiation in the 280nm-400 nm range and should not be used. However, UV absorbing filters for surrounding fluorescent tubes are available making it possible to work under fluorescent task lighting. Any UV radiation however, can fog the sensitized emulsion. Platinum is more sensitive to fogging than palladium.
Water is essential to the process. The larger the sink the more comfortable you will be processing images; efficiency increases as can the scale of the prints that you can produce. Both hot and cold water should be available.
A UV exposure unit with vacuum table is the single most important piece of equipment you can own. There are two types: single point UV light source or UV fluorescent light boxes. Single point UV light units produce increased acuity in the print and shorter exposure times. UV fluorescent light boxes are much less expensive and can require less space
The other equipment that is necessary in the darkroom include safe paper storage, microwave oven, an accurate grams scale, glass beakers, storage containers, coating brushes and / or coating rods, droppers & pipettes, darkroom trays, print washer, tongs, gloves, straightedge for paper tearing, ruler, razor knives, cutting mat, pencils, tape dispenser, spotting brushes, print dryer, electric hair dryer, back-lit viewing box for negatives.
The chemistry we recommend includes both palladium chloride and potassium chloroplatinite in either pre-mixed solution or in dry compound, ferric oxalate, potassium oxalate or / and ammonium citrate (developers), EDTA, sodium chloride, oxalic acid, Hypoclear™, Photoflo™, distilled water.
Papers for platinum and palladium printing have requirements such as no impurities, no buffering nor alkaline agents. Since the 1980s, papers such as these have been more and more difficult to obtain. The “archival” trend has been to add buffering agents to papers so that they will absorb acid in the future and remain neutral or basic in pH. As of this writing, the four main western papers that are generally accepted as being readily available and of high enough standard for Pt/Pd are Arches Platine , Bergger COT 320 , Legion Revere, and Hahnemuhle Platinum Rag.
Supplies for Finishing
Ivory black, Paynes grey and burnt umber watercolor (for spotting), Dorlands™ Wax and / or Liquitex™ Professional Gloss medium for finishing patina, acid-free blotter boards, acid-free tissue, archival print sleeves or / and archival print storage boxes.
Supplies for Piezography Digital Negative Inkjet Printing
Pictorico Ultra Premium OHP film, K6 digital negative ink set or / and Methodology 3 ink set, PiezoFlush™, spare cartridges and / or chips, inkjet negative sleeves.