Digital negative transparency

There are numerous internet sites which propose how to produce a digital negative.

Some links:

Robert Hirsch

Christina Z. Anderson

Dan Burkholder

MP Photography (especially cyanotype)

Eyes On Photography (especially cyanotype)

and more.

And of course on paper see references in previous post.

A concise handout to get started ( workshop on cyanotype):

négatif-numérique (PDF)

References alternative photography (cyanotype)

Josef Maria Eder, Rezepte, Tabellen und Arbeitsvorschriften für Photographie und Reproduktionstechnik, Verlag von Wilhem Knapp, Halle (Saale), 1942, 18.-19. Auflage.
Christopher James, The Book of Alternative Photographic Processes, Delmar , CliftonPark, 2007, 2nd ed.
Jill Enfield, Jill Enfield’s Guide to Photogrphic Alternative Processes, Focal Press, New York & London, 2014
Malin Fabri & Gary Fabri, Blueprint to cyanotypes, Malin Fabri, Stockholm, 2006
Peter Mrhar, Cyanotype, Peter Mrhar, ?, 2013

Drying sensitized paper

Use adjustable coathangers and hang the sensitized paper in a coat closet protected from light .

This technique is especially usefull for sensitized textile.  The lower hanger may be weighted for stretching!


An alternative is to use a paper box with an iron plate at the base. Small magnets keep the paper in place and prevent buckling (depends on number of magnets and the humidity of the paper). Be carefull not to touch the sensitized part and cover the iron plate with some plastic (e.g. plastic bag) to prevent unwanted chemical reactions.


Cliché verre: a wink to Corot

An further option to produce a negative for alternative printing is the cliché verre. This art form  was “en vogue” at the Barbizon School, notably Jean-Baptiste-Camille Corot and Charles-François Daubigny. Cliché verre dates back to Fox Talbot.   Later to Barbizon interest was lost in this technique which is midway to printmaking and photography. The reason here for are explained extensively in this article by  Thomas Ketelsen.  A sketch of the history of cliché verre may be found over here.

The process to create a cliché verre is quite simple: a supporting material is covered with an opaque medium into witch the the drawing is scratched, drawn or whatever you can do to modify the opacity of the plate. One of the very first techniques consisted to smoke a glass plate with a candle (here a petroleum lamp).


The soot covered glass is scratched with a needle to draw in white lines. The negative obtained this way is used to expose light sensitive paper.



exposed cyanotype:



An alternative to this would be to cover the glass plate (could as well be some other transparent support like perspex, frosted Mylar, overhead transparency) with opaque medium: gouache, oil paint, indian ink, … and draw into this like in the soot, press an object into the still wet medium or  proceed like for material printing.


The base material should present some grip so that the paint can adhere to the support.

dandelions covered with gouache on perspex:


resulting print:


Note that oil paint needs a lot of time to dry, so I would not advise to use oil paint. Instead use some water based medium.

A painting medium allows for nuances to play with.


Or a craquelure effect (uneven drying, this might be a problem) :


Further reading:

Cyanotype – In the footsteps of Anna Atkins

Sunny day today! Preparing a workshop on cyanotype printing. So out into the garden.

The idea to print plants by the cyanotype process dates back to the 19th century when Anna Atkins published the first ever book with photographic reproductions of plants (Photographs of British Algae: Cyanotype Impressions).

Yesterday I sensitized some paper with the cyanotype mixture  (J. M. Eder: Rezepte, Tabellen und Arbeitsvorschriften für Photographie und Reproduktionstechnik, Verlag von Wilhem Knapp, Halle (Saale), 1942, 18.-19. Auflage, p.225) and had it to dry overnight.



Today picked up some plants (there are plenty) and put them under glass to press them firmly onto the paper for good contact in order to have clear contours. Five minutes exposure were sufficient to get some results.


Next step: wash out the unused chemicals (more or less 20 minutes).P1000150-w.jpg




As I wasn’t happy with the colour I added some hydrogen peroxide (10% solution to the water.)






Now the very last step: let it dry.




More on cyanotype:


  • Ammonium iron(III) citrate (‘green’ variety) (important: iron(III), green)
  • Potassium ferricyanide (important: ferri not ferro) –> [Red Prussiate of Potash, rotes Blutlaugensalz, ferricyanure de potassium]


Musings in lithography: paper lithography

Lithography is in my eyes some kind of chemical, not to say alchemical printing technique. Based on the repulsion of oil and water (look at your vinaigrette 🙂 it is a planographic printmaking technique, opposed to relief and intaglio printmaking. Most common approaches use a stone, an aluminium or zinc metal plate. Modern techniques have as matrix some polymer plate (e.g. pronto plate).

Looking for a simple and low cost procedure to transfer an image to wood or metal plate for further processing I met the paper lithography (aka gum arabic transfer).

As I mentioned in my post “Inspired by Peter Freeth” I tried already once but lost the game because of a lot of crumbling of the wet paper.

Not giving up I gave paper lithography a further try. Modifying somehow my approach.

First I started with a photograph being part of my shadow series which I reproduced on a laser printer.



The decisive step this time was that I fixed this printout with gum arabic on a dibond plate, (processing as one should in paper lithography,) but instead of removing it from the base to fix it onto the press bed I passed  it with the dibond plate under the press. This avoided handling the moist paper matrix which is quite delicate.

On paper the result was more than convincing. No crumbling this time!



More on paper lithography may be found in following references:

or in these videos: