I am adding one more process to my list of photographic tools. It is called the argyrotype and is one of the many processes collectively known as siderotypes.

Siderotype is a group classification for any chemical photographic printing method based on iron. By far the most famous of these is the platinum print which, despite the name, is a member of the siderotype family and relies on iron to produce its image. In the case of all siderotypes, iron creates the image which is then converted to another metal: platinum, palladium, gold, silver, etc.

Sir John Frederick William Herschel, a British astronomer and photographic researcher discovered in 1842 that certain iron compounds could react to light and instigate a reaction with other metal compounds.

The first siderotypes were devised by Herschel himself:

  • cyanotype (more commonly know as the blueprint)
  • argentotype (silver)
  • chrysotype (gold)

The images you see on this page are some of my early tests of the argyrotype process (a 20th century improvement of Herschel’s argentotype, devised by Dr. Michael Ware), and of the enlarged negatives used to produce them. (I put five books on making digital negatives using an inkjet printer into my mental blender, then poured out a simplified approach to making digital negatives that works for me.)

Último Fotógrafo Callejero an Argyrotype
Último Fotógrafo Callejero

Over the next few decades a number of additional siderotypes were invented, more than twenty by the turn of the century, some of which include:

  • platinotype
  • palladiotype
  • amphitype
  • aurotype
  • kallitype
  • sepiatype
  • vandyke
Borracho an Argyrotype

Some siderotypes are actually recent, 20th century, developments or improvements.

  • argyrotype (an updated version of Herschel’s argentotype)
  • new chrysotype
  • ziatype
  • new cyanotype (Dr. Michael Ware, once again.)

And there are more in the list. Quite a few more.

Mujer con dos Bolsas an Argyrotype
Mujer con dos Bolsas

All siderotypes work on the same principal: make iron light sensitive, coat it onto a piece of paper, expose through a large negative using ultraviolet light, then add a certain amount of alchemy (in some cases the alchemy is included and happens automatically). If indicated, substitute a more stable metal after the print has been made. Siderotype processes produce beautiful prints, but all of the siderotypes died out in the early 20th century, and for a single reason. (In the case of platinum and palladium, prints became astronomically expensive, too.)

Entrando a la Iglesia an Argyrotype
Entrando a la Iglesia

Siderotype processes could be used only to make prints the same size as the original negative. As negatives grew smaller, siderotype printing became more and more useless. It was possible to make an enlarged duplicate negative from an original, but detail and tonality often suffered and the bigger the desired print, the more expense was involved in making that enlarged negative.

If another negative had to be made because the first wasn’t quite right, and they never were, expenses could get quite prohibitive. Despite the fact that these printing materials often far surpassed silver-based enlarging papers from the standpoint of image quality, silver-gelatin won out because enlargement was a far less expensive way to make a photograph. Any size negative, even the tiniest, could be used to make an enlarged print and the only real expense was the paper, which wasn’t very expensive, at all.

Doll & Trophy an Argyrotype
Doll & Trophy

There has been a resurgence in siderotype printing the last few decades, but the cost of enlarged negatives continued to be a problem, until digital photography came along to rescue these 19th century printing methods.

Thanks to the advent of digital photography and the work of several inventive photographers, enlarged negatives can now be made with an inkjet printer at a fraction of the cost of using specialized films for the purpose which have, by the way, completely disappeared. Digital photography has directly resulted in the revival of analog printing methods because a high quality enlarged negative is now quite economical!


I have been experimenting with the argyrotype, an improved iron process devised in 1991 by Dr. Michael Ware, based on Herschel’s original 1842 argentotype. The resulting image is composed of very fine particles of silver. Finely divided silver particles tend not to be very stable so, I am toning these prints in Kodak’s Rapid Selenium Toner which turns the silver metal into both silver selenide and silver sulfide, both very stable molecules, resulting in both a lasting and more beautiful image. (When I worked with conventional silver-gelatin papers, I always treated them with selenium, too.) At the same time, I have been learning the process of producing negatives with an inkjet printer. Difficult at first, it turns out to be mostly straightforward.

While not quite ready for prime time, I don’t expect it to be more than a few months (it is now Aug 2015) before the quality level is such that I can offer argyrotypes of my images, for sale.  When they are up to my standards, you will see them offered in the gallery.