Many modifications of this process have been proposed and practiced with more or less success. Mr. Madd, of Manchester, has perhaps, of all operators, been the most successful on large plates. The following is his mode of procedure. Coat the cleaned glass with Bromo-iodized Collodion in the usual way.


After allowing the film to set well, sensitize in the ordinary Nitrate of Silver bath. If the Collodion should give a very thick and creamy film, it must be reduced by adding Ether. After sensitizing for the usual time, the plate must be well washed and then placed in a dish containing a weak solution of Iodide of Potassium and water (about one grain to the ounce of water) for two or three minutes, gently moving the dish in the meanwhile. Rinse with tap water and drain a minute. 


To the whites of ten eggs add:

50 grains Iodide of Potassium

10 grains Bromide of Potassium

100 minims Liquid Ammonia

2 1/2 ounces Water


Dissolve the Iodide and Bromide in the Water, then add the Ammonia.

Mix all together with the Albumen, and beat the whole into a froth. Let it settle until the froth has subsided into the liquid form Filter through muslin into a stock bottle. Decant off a portion, and to the previously washed and still wet film, apply the solution twice. 


Now allow the plate to drain for five or ten minutes, then dry it rapidly before a clear bright fire, and make it quite hot. These plates may be kept till required for sensitizing. To re-sensitize the plate, it is only necessary to dip it for one minute into the Aceto-nitrate bath, with Kaolin and filtering makes it again clear; but some operators prefer to pour a little of the Nitrate solution on and off the plate for a few times, and then throw the residue into the waste-silver jar. Plates so prepared will keep in good condition for six or eight weeks in cold weather; but in hot weather it is advisable not to trust to their efficiency for more than a fortnight.


They are developed as follows. Take the exposed plate and pass over the surface a little clean water till the film is thoroughly moistened; then take a plain Pyrogallic solution, say two or three grains to the ounce of water, and pour it on the plate. The sky and highlights will appear almost immediately, if the exposure has been rightly timed, and ultimately feeble indication of details.


The picture now requires intensity, which is given by the following solution:

Pyrogallic Acid 2 grains

Citrio Acid 2 grains

Nitrate of Silver 2 or 3 drops (20 grain solution)


Pour quant. suff . of this on and off the plate until the requisite printing density is obtained. Numerous modifications of this excellent dry process have been devised and worked, but the above may be considered a good starting point for the Photographer to alter according to his tastes.


The Negatives should be fixed with Hyposulphite of Soda, because Cyanide of Potassium will always weaken or destroy the semi-organic deposit, just as surely as if the image were a Positive print on paper.



Collodio-Chloride Prints; aka Aristotypes


Edward Curtis Photogravures

Greetings! We had a visit today from Paul Unks (some of you good folks out there know him, I'm sure). Paul is a great guy; we had good conversation and Jeanne and I learned a lot about Edward Curtis.

I've always loved Curtis' prints. I studied him in undergraduate school; his work resonated on many levels for me. It was the first body of work that showed me that the line between "documentary work" and "fine art work" could be blurred, or mixed together, or morph into something truly original. It was a photographic epiphany for me. I believe that was in 1989.

I've only seen a few photogravures from Curtis in my life (Denver Art Museum); however, that all changed today. Paul brought a lot of "continuation work" and we had the honor to see it. Absolutely gorgeous. What a treat! I could bather on about it, but you know how good it is.

Paul is friends with John Graybill. John is Edward Curtis' g-great-grandson. John, and his wife, Coleen, spent the day here Friday - we've had a great weekend! Need I say more?

Paul with his Edward Curtis photogravure, "Canton de Chelly, Navajo" (forgive the crappy repro digi phone and reflections; you get the idea).
Quinn, Jeanne, and Paul with "Canyon de Chelly" - Edward Curtis
Beautiful!! Photogravure - Edward Curtis' "Cayon de Chelly, Navajo"

Learn to Argue with Logic


Critical Thinking

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