Editing Platinum print

{{Short description|Type of photographic print}}
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[[File:Coming Home from the Marshes, Peter Henry Emerson, 1886.jpg|upright=1.35|thumb|''Coming Home from the Marshes'', platinum print by [[Peter Henry Emerson]], 1886]]
{{Alternative photography}}
'''Platinum prints''', also called ''platinotypes'', are photographic prints made by a [[monochrome]] [[photographic printing|printing]] process involving [[platinum]].

Platinum tones range from warm black, to reddish brown, to expanded mid-tone grays{{Clarify|reason=The phrase "expanded mid-tone grays" is vague. Please explain what expanded means and in comparison to what.|date=April 2014}} that are unobtainable in silver prints.<ref>
{{cite web
 |url        =http://www.ellwoodcityledger.com/news/local_news/photographer-now-calls-former-fombell-post-office-home/article_81f71dcf-fd3d-5b2c-b267-31002eb483fb.html
 |title      =Photographer now calls former Fombell post office home
 |last       =Poole
 |first      =Eric
 |date       =2013-01-21
 |website    =ellwoodcityledger.com
 |publisher  =Ellwood City Ledger
 |access-date =2013-07-27
}}
</ref>{{Dubious|Comparison of platinum print vs silver-gelatin print tonality|reason=Please state which tones are unobtainable in silver prints. The referenced interview only suggests that "Platinum photo processing is still highly regarded from an artistic standpoint, Klimek said, because it captures the range of shades between black and white better than silver-based processing." but it does not speak of unobtainable tones. Further, this is not a precise statement.|date=April 2014}}

Unlike the [[Gelatin silver process|silver print process]], platinum lies on the paper surface, while [[silver]] lies in a [[gelatin]] or [[Albumen print|albumen]] [[emulsion]] that coats the paper. As a result, since no gelatin emulsion is used, the final platinum image is absolutely [[Paint sheen#Terminology|matte]] with a deposit of platinum (and/or [[palladium]], its sister element which is also used in most platinum photographs) absorbed slightly into the paper.<ref name="collectors-guide">{{cite web|url=http://www.collectorsguide.com/fa/fa031.shtml#RESOURCES |title=The Collector's Guide: Platinum Photography |publisher=Collectorsguide.com |date=2007-09-24 |access-date=2013-07-28}}</ref>

Platinum prints are the most durable of all photographic processes.{{Dubious|Durability|reason=Carbon prints are also claimed to be durable. Further, in the case of any prints, durability (or lack of) of the paper support should be mentioned.|date=April 2014}} The [[platinum group]] metals are very stable against chemical reactions that might degrade the print—even more stable than [[gold]]. It is estimated that a platinum image, properly made, can last thousands of years.<ref name="collectors-guide"/> Some of the desirable characteristics of a platinum print include:
* The reflective quality of the print is much more diffuse in nature compared to glossy prints that typically have [[Specular reflection|specular reflections]].
* A very delicate, large [[Dynamic range|tonal range]].
* Not being coated with gelatin, the prints do not exhibit the tendency to curl.
* The darkest possible tones in the prints are lighter than silver-based prints. Recent{{When|date=April 2014}} studies{{Citation needed|reason=DMax is not an optical illusion but an arguably complex, yet absolute measurement of reflectance. DMax of Se toned Ilford WT glossy paper reaches 2.4 which is close to theoretical maximum. Waxed platinum prints discussed on APUG.org quote DMax of 1.8, which is significantly less. It would be good to quote the studies referenced in this statement, especially if the effect is due to an illusion rather than measurable data.|date=April 2014}} have attributed this to an [[optical illusion]] produced by the gelatin coating on Resin Coated and fiber-based papers. However, platinotypes that have been waxed or varnished will produce images that appear to have greater maximum density than silver prints.
* A decreased{{quantify|reason=Statements of durability and permanence are not meaningful unless specific.|date=April 2014}} susceptibility to deterioration compared to silver-based prints due to the inherent stability of the process and also because they are commonly printed on 100% [[Cotton paper|rag papers]].
Many{{How many|date=April 2014}} practitioners have abandoned platinum and only use palladium.{{Citation needed|reason=Contemporary platinum prints are available for purchase from galleries, suggesting that this process has not been abandoned, therefore it would be helpful to quote some references to support the statement to the opposite.|date=April 2014}} The process using palladium alone ([[sodium tetrachloropalladate]]) is similar to standard processes, but rather than using [[ferric oxalate]] plus [[potassium chlorate]] as the restrainer (which is ineffective for palladium), a weak solution of [[sodium chloroplatinate]] is used instead.  Sodium chloroplatinate, in contrast to potassium chlorate, does not cause [[Film grain|grain]]. This formula is generally referred to as the ''Na2 method''. This somewhat misleading abbreviation was coined by Richard Sullivan of Bostick & Sullivan, one of the principal suppliers of chemistry and printing supplies, who popularized the process.

== History ==
The first person to have recorded observing the action of light rays on platinum was [[Ferdinand Gehlen]] of Germany in 1830. The following year, his countryman, [[Johann Wolfgang Döbereiner|Johann Wolfgang Dobereiner]], determined that the action of light on platinum was quite weak, but that perhaps something could be combined with platinum to increase its sensitivity. Through experimentation, he eventually found that [[ferric oxalate]] was a highly-effective enhancer. The combination of these two metals remains the basis of the platinotype process in use today.<ref name="TPP">John Hafey & Tom Shillea. [https://web.archive.org/web/20131228084318/http://www.kimeia.com/pdf/history.pdf The Platinum Print & The History of the Platinum Process]. kimeia.com</ref>

In 1832, Englishmen [[John Herschel|Sir John Herschel]] and [[Robert Hunt (scientist)|Robert Hunt]] conducted their own experiments, further refining the chemistry of the process. In 1844, in his book ''[[Researches on Light]]'', Hunt recorded the first known description of anyone employing platinum to make a [[Photographic printing|photographic print]]. However, although he tried several different combinations of chemicals with platinum, none of them succeeded in producing any permanency in the image. All of his prints faded after several months.

Over the next decade, Hunt noted that platinum prints he had left in the dark faded very slowly but gradually resumed their original density, and had also shifted from a [[Negative (photography)|negative]] to a [[Positive (photography)|positive image]], eventually becoming permanent.<ref name=TPP />

By the early 1850s, however, other more reliable photographic processes, such as [[salt print|salt]] and [[albumen print|albumen]] printing, had been developed and were beginning to be widely used. Those scientists who had previously conducted research on platinum lost interest in the process as other methods became more commercially viable. The only major advances in platinum research reported during that decade were made independently by [[C.J. Burnett]] and Lyonel Clark of Great Britain. In 1859, Burnett published an article in the ''[[British Journal of Photography]]'' describing his use of sodium chloroplatinate as a [[fixing agent]]. His modification of the platinum printing process resulted in prints that were permanent enough that he could exhibit them in public. That same year, Clark also exhibited prints made using a slightly different process.<ref name="TPP" />

== Patents ==
[[William Willis (inventor)|William Willis]] was the first to patent the platinotype process in 1873  (British Patent No. 2011, June 8, 1873),<ref name=TPP /> and again in 1878 and 1880, which he leveraged to gain commercial success in the manufacture of platinum papers sold through his Platinotype Company for [[Commercial photographer|professional]] and [[Amateur photography|amateur]] use.  He also developed the palladium process requiring palladiotype paper and a silver-platinum paper, [[Satista]].<ref name=encyclopedia>{{cite encyclopedia | encyclopedia = Encyclopedia of Nineteenth-Century Photography | volume=1 | section=A-I | year = 2008| editor1-last = Hannavy | editor1-first = John | publisher = Taylor and Francis Group, LLC | location = New York, NY | isbn = 978041597235-2 | url=http://home.fa.utl.pt/~cfig/Anima%E7%E3o%20e%20Cinema/Fotografia/Enciclopedia%20of%20the%2019th%20Century%20Photography.pdf | title=Encyclopedia of nineteenth-century photography: A-I, index }}</ref>

Willis introduced the "[[hot bath]]" method where a mixture of ferric oxalate and potassium chloroplatinate are coated onto paper which is then exposed through a negative and developed in a warm solution of potassium oxalate.<ref name=HPP>{{cite web|url=http://www.danesphoto.com/pt_history.html |title=History of the Platinum Print |publisher=Danesphoto.com |access-date=2013-07-28}}</ref>

== Commercialization ==
While Willis had greatly advanced the chemistry of the platinum process, there was still no reliable method for the individual preparation of platinum paper by 1880. Two years, later two [[Austrian Armed Forces|Austrian Army]] officers, [[Giuseppe Pizzighelli]] and [[Arthur Baron V. Hubl]], published a [[Thesis|dissertation]] describing a straightforward process for preparing the paper. They continued their research for several years, and in 1887, Pizzighelli patented a new process that made the commercial production of platinum paper viable for the first time. The new process was briefly known as a "[[Pizzitype]]" and was marketed under the name "Dr. Jacoby's Printing Out Paper."<ref name=Eder>{{cite book| author=Josef Maria Eder|title=The History of Photography|publisher=NY: Columbia University Press|date=1945|page=545}}</ref>

Willis quickly countered this advance by obtaining two more patents in 1888 for cold-bath processes. By adding more platinum to the developing process, he produced prints that had dense brown-black shadows rather than the lighter browns that were the best that previous processes could produce. While much more aesthetically pleasing, prints developed by this process were difficult to produce reliably.

Four years later, Willis began manufacturing a platinum paper that was designed for the cold-bath process, and this became the standard for the rest of the decade. The business he started in 1880, called the Platinotype Company, rapidly expanded, and soon he was selling his paper throughout Europe and in the United States. By 1906, his company had sales totaling US $273,715 (${{formatnum:{{inflation|US|273715|1906|2009}}}} in 2009 dollars), a significant amount at that time.<ref name=TPP />

Seeing the skyrocketing demand for platinum paper, the [[Eastman Kodak]] Company in [[Rochester, New York]], tried to develop its own line of paper starting in 1901, but they could not duplicate the quality of Willis's product. Kodak then tried to buy Willis's company but was not able to come to an agreement. Kodak instead bought the relatively new company of [[Joseph Di Nunzio]] who had recently developed his own brand of platinum paper comparable to Willis's, which he sold under the name of "Angelo".  Kodak continued to sell this paper for several years before it was eventually discontinued.

When Willis began marketing his paper, platinum was relatively cheap. By 1907, platinum had become 52 times more expensive than silver. Eastman Kodak and most other producers stopped fabrication of the paper in 1916. [[Russia]] controlled 90% of the world platinum supply in [[World War I]] and all available platinum was used in the war effort. Nevertheless, platinum paper has continued in use until the present, interrupted only by the world wars.

Beginning in 1964, [[Irving Penn]] began experimenting with platinum printing. Penn had spent his career up to that point making photographs that were seen almost exclusively in reproduction within the glossy pages of magazines and in his pivotal 1960 book ''Moments Preserved''. Penn set himself the challenge of producing photographic prints that would surpass the technical limitations of reprographic media and deliver a deeper visual experience. He was drawn to the antiquated platinum process for its long grayscale – its ability to display a seemingly infinite array of gradations between pure white and absolute black.

The platinum process requires direct contact with the negative, without enlargement, so Penn first needed to create flawless negatives the same size as the desired print. He then hand-coated paper with platinum emulsion. When dry, the paper was sandwiched with the negative and exposed to light before processing. Rigorous experimentation revealed that recoating a print with a secondary emulsion and making a second or third exposure of the same image on a single sheet of paper yielded prints of greater depth and subtlety. Penn solved the problem of aligning and re-aligning the negative and the print surface over multiple exposures by borrowing a technique from the graphic arts: he mounted his paper on a sheet of aluminum with a series of registration guides along the top edge. Penn was guarded about the preparation of his emulsions and his precise formulations varied considerably. He frequently introduced palladium and iron salts into his coatings to achieve desired effects.<ref>{{cite web | url=https://www.phillips.com/detail/irving-penn/NY040123/177 | title=Irving Penn - Photographs New York Tuesday, April 4, 2023 }}</ref>

==Palladium==
In [[photography]], the ''palladiotype'' is a less-common variant of the platinotype. The process came into greater use after World War I because the platinum used in the more-common platinotype quickly became too expensive. Due to the rising cost and the consequent shortage of commercial platinum paper, photographers tried to replace the platinum with the much cheaper palladium which gave similar effects. The cost of this metal, however, also started to rise and eventually around 1930 the process was abandoned in favor of more economical alternatives. In recent years, a handful of photographers have taken up the art of mixing platinum and palladium and printing fine art prints with those chemicals, despite its cost.

Characteristics of a palladium print, compared to a platinum print:
*A warmer tone
*Easier to solarize (see the [[Sabatier Effect]])
*Large tonal range, up to D= 2.1, thus requiring a contrast-rich negative for printing
*Deeper blacks, with a higher maximum density
*A softer image, with delicate highlights

==Chemistry==
Platinum printing is based on the [[Photochemistry|light sensitivity]] of [[ferric oxalate]]. Ferric oxalate is reduced to [[ferrous oxalate]] by [[UV-light]]. The ferrous oxalate then reacts with platinum(II) or palladium(II) reducing it to elemental platinum (or palladium), which builds up the image.

By varying the amount of platinum versus palladium and the addition of oxidizing chemicals such as [[hydrogen peroxide]] and [[potassium dichromate]] or [[potassium chlorate]], the contrast and "color" of the final image can be modified. Because of the non-uniformity of the coating and mixing phases of the process, no two prints are exactly the same.

In 2002, working from research done by Howard Efner and Richard Sullivan, Dick Arentz formulated the methodology for using sodium chloroplatinate as a contrast control agent. Richard Sullivan coined the term Na2 and began to sell a 20% solution through Bostick and Sullivan. Arentz found that, since it is a platinum compound (sodium chloroplatinATE), it does not work with platinum prints (potassium chloroplatinITE). It does, however, shorten the scale of a pure palladium print. When minute quantities of sodium chloroplatinate are added to the palladium salt/ferric oxalate emulsion it produces the high-contrast prints needed for thin negatives, but does not exhibit the granularity found when using traditional chlorates. A palladium print made with potassium chlorate will take on a warm, sepia tone. The same print using sodium chloroplatinate will have cooler tones similar to those of a platinum/palladium print.
 
The inherent low sensitivity of the process occurs because the ferric oxalate is sensitive to [[ultraviolet light]] only, thus specialized light sources must be used and exposure times are many times greater than those used in silver-based photographic processes.
 
Due to the unavailability of pre-coated sensitized paper, all platinum/palladium printing is done on paper coated by the printer. The light sensitive chemicals are mixed from powdered basic chemicals, or some commercially available solutions, then hand applied with a brush or a cylindrical "pusher".
 
Many artists achieve varying effects by choosing different papers for different surface characteristics, including [[vellum]], 100% cotton rag, silk, and rice, among others. On the collecting market, platinum prints often sell for many times what a similar silver-gelatin print would bring.

==Notable photographers using the technique==
<!-- Please respect alphabetical order. 
     This list does not need to be complete. -->
{{Div col|colwidth=22em}}
* [[Dick Arentz]]<!-- Wrote the book on it -->
* [[George Charles Beresford]]
* [[Manuel Álvarez Bravo]]<ref name="collectors-guide" />
* [[Alvin Langdon Coburn]]
* [[Lois Conner]]
* [[Imogen Cunningham]]
* [[Edward S. Curtis]]<ref name="collectors-guide" />
* [[F. Holland Day]]
* [[Dazeley]]
* [[Olive Edis]]
* [[Frederick H. Evans]]
* [[Laura Gilpin]]<ref name="collectors-guide" />
* [[Naohisa Hara]]
* [[Frederick Hollyer]]
* [[Gertrude Kasebier]]
* [[David Michael Kennedy]]
* [[Sal Lopes]]
* [[Gilles Lorin]]
* [[Robert Mapplethorpe]]
* [[Andrea Modica]]
* [[Tina Modotti]]
* [[Isabel Muñoz]]
* [[Irving Penn]]<ref name="collectors-guide" />
* [[Ted Preuss]]
* [[Sebastiao Salgado]]
* [[Tom Sandberg (photographer)|Tom Sandberg]]
* [[J. Shimon & J. Lindemann]]
* [[Edward Steichen]]
* [[Alfred Stieglitz]]<ref name="collectors-guide" />
* [[Paul Strand]]<ref name="collectors-guide" />
* [[George A. Tice]]
* [[Robert Vano]]
* [[Edward Weston]]<ref name="collectors-guide" />
* [[Clarence Hudson White|Clarence H. White]]<ref name="collectors-guide" />
*  
{{div col end}}

==See also==
* [[Photographic processes]]

==References==
{{reflist}}

==Further reading==
*{{Cite book |last=Malde |first=Pradip |title=Platinotype: making photographs in platinum and palladium with the contemporary printing-out process |last2=Ware |first2=Mike |date=2020 |publisher=Routledge |isbn=978-0-367-41595-2 |series=Contemporary practices in alternative process photography |location=London New York}}
* {{cite journal
| author= Mike Ware
| title = An Investigation of. Platinum and Palladium Printing
| journal = Journal of Photographic Science
| year = 1986
| volume =  34
| issue = 5–6 
| pages = 165–177
| url =  http://www.mikeware.co.uk/downloads/Palladium_Printing.doc }}
* {{cite journal
| author =  Mike Ware
| title = Book Review of : Photography in Platinum and Palladium
| journal = Platinum Metals Review
| volume = 49 
| issue = 4
| pages = 190–195
| year = 2005
| doi = 10.1595/147106705X70291| doi-access = free
}}
* Dick Arentz. Platinum & Palladium Printing, Second Edition. Focal Press. 2004

== External links ==
{{Commonscatinline}}

{{Photography}}
{{DEFAULTSORT:Platinum Print}}
[[Category:Photographic processes dating from the 19th century]]
[[Category:Printing technology]]
[[Category:Alternative photographic processes]]