Historical Photographic Processes and Modern Experimentation

Platinum/Palladium Print

The process for making platinum prints was invented in 1873 by William Willis. The process depends on the light sensitivity of iron salts to produce an image. This process depends on replacing the iron salts with platinum or palladium in the final print. Many present practitioners use a combination of platinum and palladium for a single image. When used alone, platinum prints have a tonal range that is generally considered cooler than palladium prints. Whether used alone or together, platinum/palladium prints are highly valued for their great range of subtle tonal variations, producing deep rich shadows and detail-filled highlights with a great degree of permanence.

Carbon Print/Carbon Transfer

Carbon is a contact printing process that gives a final image that comprises a pigment suspended in gelatin placed on a final support, usually paper. To make this image a negative is placed in contact with a sensitized sheet of carbon tissue and exposed to an ultraviolet light source. This causes the gelatin to harden directly in proportion to negative densities, i.e. the tissue is hardened more in the shadows than in the highlights. After exposure, the tissue is soaked briefly in cool water, then squeegeed into contact with a paper or plastic support. After water development, the pigmented gelatin has begun to melt the tissue is peeled from the support and discarded.


Chemigram is a combination of both painting and photography and lies within the general domain of experimentation in the visual arts. It requires the use of materials from silver halide-based photography (light-sensitive paper, developer, and fixer), but it is not a photograph. Like the photogram, the chemigram is made without a camera, yet it is created in full light instead of in the darkness of the darkroom. For this reason, it is not “light that writes” (photo graphein in the Greek) but rather “chemistry that writes” Chemigrams can be made solely with photo paper, developer and negative/positive film.

Chromogenic Print (C-Print)

Chromogenic colour prints are full-colour photographic prints made using chromogenic materials and processes. These prints may be produced from an original, which is a colour negative, slide, or digital image. The chromogenic print process was nearly synonymous with the 20th-century colour snapshot. The first commercially available chromogenic print process was Kodacolor, introduced by Kodak in January 1942. Kodak introduced a chromogenic paper with the name Type-C in the 1950s, and then discontinued the name several years later, although the terminology of C-Print or Type-C is still used today.


Invented by Sir John Herschel in 1842, cyanotypes can be easily identified by their brilliant blue colour. The chemicals used for this process are very inexpensive, simple to formulate and produce a very permanent image. Ferric ammonium citrate and potassium ferricyanide are mixed into a solution and coated onto the surface of the paper. This light-sensitive paper is exposed to ultraviolet light under a photographic negative or object to create a positive image in a stable deposit of what is known as Turnbull’s blue. This process was not commonly used after Its discovery, yet it found resurgence during the 1880’s with the introduction of the hand camera and the amateur photographer.

Gelatin Silver Print

Through the 20th century, the gelatin silver process has been the ubiquitous process for making black and white photographic prints from negatives. The process uses commercially produced papers, coated with a layer of gelatin containing light-sensitive silver salts. When exposed to light, a latent image is produced that becomes visible when developed in a reducing agent (the developer) and then fixed to remove the remaining light-sensitive silver halides. This process was introduced in the 1870s, and by 1895 had generally replaced albumen prints as a result of their increased image permanence and ease of production.

Gum Bichromate Print

This process has often been credited to John Pouncy, who in 1858 patented a pigment printing process using a bichromated salt, gum arabic and a pigment. His process was a further development of the experiments and patents of Alphonse Louis Poitevin in 1855, Robert Hunt in 1843, Alexandre. Edmond Becquerel in 1840, and Mungo Ponton in 1839. Ponton first discovered the light sensitivity of paper soaked in a solution of potassium
bichromate. A gum bichromate print is the result of a pigment (most often a water colour) suspended in gum arabic, combined with a bichromated salt, deposited in varying degrees of relief onto a paper substrate, exposed to ultraviolet light under a photographic negative, and finally developed in warm water.

Lumen Print

Lumen prints are made by taking sheets of unexposed black-and-white photo paper and placing objects or negatives on top as if you were going to make a photogram, but instead of using an enlarger you take the paper out into the sun. The results will vary due to exposure times, density of photogram or negative, quality of light and, most importantly, the type of paper. Each paper will have a different color, depending on whether it was
old or new, fiber or resin, and the manufacturer. Exposures can vary from half an hour to days and sometimes even months.


Mordançage is an alternative photographic process that alters silver gelatin prints to give them a degraded effect. The mordançage solution works in two ways: it chemically bleaches the print so that it can be redeveloped, and it lifts the black areas of the emulsion away from the paper giving the appearance of veils. Once the emulsion is lifted, it can then be removed or manipulated depending on the desired outcome. These prints can become
oxidized during their creation, further altering the tonality of the image.

Salt Print

Invented by William Henry Fox Talbot in 1839, the salted paper print was the earliest form of a photographic positive on paper. It remained the most common paper printing process until the 1850’s when the albumen process was introduced. Salt prints are produced by coating paper with the light-sensitive chemical silver nitrate and sodium chloride resulting in prints with varying shades of brown or sepia with a typically low contrast matte surface.


Invented by Aldolphe Alexandre Martin in 1853, tintypes are created on enamelled or blackened thin iron plates and coated and processed using the same chemistry used in the ambrotype process. The resulting positive image on the metal plate is washed, dried, and given a protective coating of clear varnish. The tintype became very popular in the U.S. especially during the Civil War primarily due to its low cost and durability. Historically, the main period of use of tintype was from 1856 through the mid-1880s.

Van Dyke/Kallitype Print

Kallitype is a member of the family of iron-based printing processes and is a close cousin to platinum print. It was first named and explained by Sir John Herschel in 1842 with the principles later developed and patented in 1889 by Dr. W. W. J. Nicol. Although the Van Dyke and Kallitype processes are quite similar, both being based on the light sensitivity of iron salts, each has its own unique characteristics.


The Ziatype is a variation of the Pizzighelli POP process that uses lithium
palladium chloride (lithium chloropallidite) as the primary metal and
ammonium ferric oxalate for the iron compound to produce a continuous
tone print. Colour and contrast are controlled chemically, unlike other
Pizzighelli processes where colour and contrast are controlled by humidity.
The Ziatype was originated by Richard Sullivan of Bostick and Sullivan and
tested to perfection by Carl Weese.

Current Practitioners

Marc Lenot

In 2005, after a career as an economist following studies at the École Polytechnique and the Massachusetts Institute of Technology, Marc Lenot (b. 1948) reinvented himself as an art critic. Since then, he has been writing an online reference blog on contemporary art, Lunettes Rouges, published by Le Monde. In 2009 he obtained a master’s degree from the School of Advanced Studies in the Social Sciences (EHESS) in Paris with a thesis on the Czech photographer Miroslav Tichý. In 2016, under the guidance of Michel Poivert, he obtained a PhD from Paris Sorbonne University with a doctoral thesis on experimental photography, partly based on Flusser’s concepts. His book on the same subject, Jouer contre les Appareils, was published in June 2017 by Éditions Photosynthèses in Arles. He was the first “digital” member of AICA (International Association of Art Critics) in France, and in March 2014, competing with nine other French art critics, he won the AICA France Art Critic Prize, awarded by a jury international.

Justin Quinnell

Justin Quinnell lectures at Falmouth University and is considered a world expert in pinhole photography and camera obscura, which he has taught for over 28 years all over the world. His work includes ‘Mouthpiece’: images between mouths, ‘Slow Light’, 6-month exhibitions and ‘Awfullogrammes’. Justin was a pinhole photography consultant for the Rachel Weisz – Mark Ruffalo film The Brothers Bloom and the NASA website. He has appeared several times on TV shows and has published three books, most recently ‘Discovering Light’. Justin is the director of the Real Photography Company.

Celica Veliz

Photographer, teacher of visual arts and ceramist technique. She trained in the city of Tandil at IPAT and the Provincial School of Ceramics. At the end of her studies, she began to investigate and experiment with the photographic techniques of the 19th century. She currently coordinates pinhole photography workshops, b & n laboratory and alternative photographic processes in her virtual space Sensitive Surfaces and in the Image Cooperative of Buenos Aires. She has given workshops and talks in several cities in Argentina and Mexico. In 2019 she presented the project El Cuerpo Roto at the Emilio Petorutti Provincial Museum of Fine Arts in La Plata and in Mumbat Tandil. Her previous solo shows were Bosque Cerrado in Mumbat (2013) and MADER in Nova Galería, La Plata (2016). Her work was also part of the exhibitions Visaje in the Artemio Gallery (Tandil), Self-portraits/pinhole in Common Space (Monterrey, Mexico) and those selected for the 2015 Francisco Ayerza Award (Museo Sívori, CABA). One of her works, The Missing Parts, was selected in the 2019 Visual Arts Contest of the National Endowment for the Arts. She has participated as a workshop facilitator, speaker and exhibitor at the festivals Tranza 2018, Coven Blue, CCNoche, Western Photographic, Festival of Light, Graphic Pressure, An Image for Culture (Ecuador / Colombia), 30 Photograms and Photo Patagonia, among others.


Experimental Books by Pablo Giori

Pablo is one on the principal organizers behind the Experimental Photography Exhibition and the Agora Experimental Group. Here are some of the books that he has in my collection (and others that he wants to buy) and that can help deepen an experimental practice.

General Books

  • Photography: A Middle–Brow Art by Pierre Bourdieu (1996)
  • Towards a Philosophy of Photography by Vilém Flusser (2000)
  • Una filosofía de la fotografía de Vilém Flusser (2001)
  • Experimental Photography: A Handbook of Techniques by Luca Bendandi (2015)
  • Fotografía experimental: Manual de técnicas y procesos alternativos de Luc Bendandi (2015)
  • Jouer contre les appareils: De la photographie expérimentale by Marc Lenot (2017)
  • Science for the Curious Photographer: An Introduction to the Science of Photography by Charles S. Johnson (2017)
  • 52 Assignments: Experimental Photography by Chris Gatcum (2018)
  • Film Photography Handbook,The: Rediscovering Photography in 35mm, Medium, and Large Format by Chris Marquardt (2019)
  • La cámara lúcida: Nota sobre la fotografía by Roland Barthes (2020)
  • EXP.20 Manifest
  • EXP.21 Movement
  • Alternative Process Photography for the Contemporary Photographer: A Beginner’s Guide by Morgan Post (2022)
  • Re·source by Sustainable Darkroom (2022)
  • EXP.22 Catalogo | Cataleg + Libro teórico: STUDIES ON EXPERIMENTA PHOTOGRAPHY by Marc Lenot, Ludimilla Carvalho, Sergio Minniti, Edd Carr and Roberta Valtorta.

Creative and Play

  • Oblique Strategies Cards by Brian Eno (1975)
  • The photographer’s playbook: 307 Assignments and Ideas by Jason Fulford (2014)
  • Wicked arts assignments: practising creativity in contemporary arts education by Emiel Heijnen and Melissa Bremmer (2020)
  • Estrategias Creadoras (2019) y Preguntas Creadoras (2020) cartas de Creadores de Imágenes


  • Thinking About Exhibitions by Bruce W. Ferguson, Reesa Greenberg, Sandy Nairne (1996)
  • Diseño de exposiciones: Concepto, instalación y montaje de Luis Alonso Fernández y Isabel García Fernández (2010)
  • Curator’s Handbook by Adrian George (2015)
  • Ways of Curating Tapa blanda by Hans Ulrich Obrist (2016)
  • Diseño de exposiciones de Hughes Philip (2019)


  • Structure of the visual book by Keith Smith (1984)
  • LIBRO. UN ENSAYO SOBRE EL LIBRO DE FOTOGRAFIA: Un ensayo acerca del libro de fotografía y de su momento actual en España de Eloi Gimeno, Horacio Fernandez, Jon Uriarte (2014)
  • FENÓMENO FOTOLIBRO de Moritz Neumüller (2017)


  • Techniques
  • The Darkroom Handbook by Michael Langford (1984)
  • Lomo Life: The Future is Analogue: The Cameras The Story by Lomography and Neil Gaiman (2012)
  • Darkroom Dynamics: A Guide to Creative Darkroom Techniques – 35th Anniversary Annotated Reissue by Jim Stone (2016)
  • Photographic Possibilities: The Expressive Use of Concepts, Ideas, Materials, and Processes by Robert Hirsch (2017)
  • Jill Enfield’s Guide to Photographic Alternative Processes: Popular Historical and Contemporary Techniques by Jill Enfield (2020)
  • The Experimental Darkroom: Contemporary Uses of Traditional Black & White Photographic Materials by Christina Anderson (2022)

Film Soup

  • Film Soup: A guide for experimental photography with analogue films by
  • Hanalogital (2022)

Film Swap and Double Exposure

  • Unexpected Inhabitants. 12 key ideas on Film Swap y Double Exposure by Pablo Giori (2019)
  • Tratado de fotografía desobediente de Blanca Viñas (2020)


  • La guía creativa de Polaroid de Rhiannon Adam (2017)
  • Polaroid: The Complete Guide to Experimental Instant Photography by Rhiannon Adam (2017)

Printing Technique

  • Risografía. El nuevo espíritu de la impresión de Luca Bendandi (2017)


  • Pinhole Photography: From Historic Technique to Digital Application by Eric Renner (2008)


  • Cyanotype Toning: Using Botanicals to Tone Blueprints Naturally by Annette Golaz (2021)