Alt-Process Prints from Digital Negatives or Positives

[bob carnie]

Flashing with Gum

Never tried but has anyone tried coating a colour down on existing image and exposing , I am trying to fill in some highlight detail and wondering if this will work for me. would love
to hear any experience opinions on this.

[sanking]

A three-color carbon assembly print on acrylic sized Melinex 339, about 7.5" X 11" in size.

Subject was wall art in Oaxaca, Mexico.

Sandy

[sanking]

And a more traditional looking monochrome print, Ossabaw Reflections.

15" X 23" carbon transfer print (image size) on home made carbon tissue, transferred to 19"X25" Canson art paper, sized with GAD (Gelatin + Albumen + Dichromate), with sun hardening. The original digital file, stitched from image capture with a Sony a7r on Cambo Actus, was about 250 MP so detail is about on par with what one would expect from a 5X7" negative at this print size.

From a digital negative printed with an Epson 7800, with QTR and a QTR profile calibrated for this tissue, which was made with 14 parts Dick Blick Black Cat + 2 parts of Mixol Violet (per liter of pigmented gelatin).

Sandy

[koraks]

Sandy, your work is stellar, as always. I just can't believe the vividness of that color print. I've been reading a bit about dye transfer lately and it seems that color carbon transfer is the only remaining process up there at that level in terms of gamut and longevity (and arguably, it's superior).

Could you tell us a bit more about the sizing of the final support? You mention a combination of gelatin and albumen; I assume in separate coatings? Do you harden the albumen with dichromate as well? I've switched from chrome alum to formalin hardening with gelatin, which seems to work brilliantly, as long as I coat at least 3 layers of gelatin. I did some experimentation with albumen, but on its own, it seems to be too thin to allow the tissue to adhere even though the albumen does seem to be nice and sticky (if you get what I mean); do you use the gelatin for its swelling and supercoat with albumen for its adherence properties?

[sanking]

Sandy, your work is stellar, as always. I just can't believe the vividness of that color print. I've been reading a bit about dye transfer lately and it seems that color carbon transfer is the only remaining process up there at that level in terms of gamut and longevity (and arguably, it's superior).

Could you tell us a bit more about the sizing of the final support? You mention a combination of gelatin and albumen; I assume in separate coatings? Do you harden the albumen with dichromate as well? I've switched from chrome alum to formalin hardening with gelatin, which seems to work brilliantly, as long as I coat at least 3 layers of gelatin. I did some experimentation with albumen, but on its own, it seems to be too thin to allow the tissue to adhere even though the albumen does seem to be nice and sticky (if you get what I mean); do you use the gelatin for its swelling and supercoat with albumen for its adherence properties?

Hi Koraks,

Thanks for your remarks.

With regard to the color print, color carbon was capable of equal gamut and greater longevity than dye transfer, but dye transfer was easier and faster to work so in the end it prevailed and replaced color carbon as the commercial standard for very high end color printing. The gamut of current inkjet worker is superior to both color carbon and dye transfer, but in terms of longevity color carbon is still superior.

Why the combination of gelatin + albumen? You pretty much put your finger on the problem in noting that in sizing art papers a lot of gelatin is needed to assure a good transfer. This could be achieved with several coats, as you have apparently done, or with one very thick coat. Another issue is that the hardening with formalin is a function of time and strength, and if you store the papers without washing some fumes may remain that can harden the tissue. You could wash the hardened paper to eliminate this possibility, but there is another time consuming step.

Albumen works really well in a very thin coat, perhaps about 1/5 as thick as what you would need with a gelatin size. Unfortuantely, it is impossible to apply a very thin coat of albumen to a cotton rag paper because the thin albumen coating is absorbed in part by the paper fibers. So for albumen to work well with carbon printing you need to apply a thick coat, or several thin coats.

The solution I have found is to mix a thin gelatin solution (about 4%) with liquid albumen, about 2 parts gelatin + 1 part liquid albumen, or 3+1 and coat the paper with this combination. To this I add about 1% of a 5% solution of dichromate. If this is done at the right temperature the coating will set on top of the paper in about five minutes, after which you place it on a drying panel to dry. When dry you hang the paper on a clothes line outside in the sun and the dichromate will harden the coating in a relatively short period of time.

I apply the sizing in one coating. The paper is first soaked in water, then squeegeed to a flat and even surface (glass plate for example). The gelatin + albumen + dichromate is mixed, poured on the paper and spread with a brush evenly, but leaving a large bead at one end. Then a mayer rod is shoved over the surface from one side to the other. What is left is a thin coating, very even, that will set up in about five minutes. For sizing paper I use a RD95 threaded rod, with thread depth of about 0.095", or about 0.2 mm. The thickness left after applying the solution is around 0.1 mm. For a 20" X25" sheet of art paper I use typically 40 ml of 4% gelatin and 20 ml of liquid albumen, plus about .5 ml of a 5% solution of ammonium dichromate. The 60 ml is about 2X the actual amount needed to coat the paper to a thickness of about 0.1 mm (which can be calculated by multiplying in cm width X length X height of the coating, but the excess is needed to assure even coating.

Sounds complicated but once you learn the technique the actual coating process goes very fast. For example, yesterday in about a 2.5 hour period I coated 20 sheets of 20X26" Arches Aquarelle paper. It is now outside drying in the sun, and I would be able to use it for carbon printing in about two hours.

You could also coat with this method using only gelatin solution + dichromate, but you would need a stronger gelatin percentage of at least 6%, and the coating would not have as much sheen. And even a 6% gelatin solution applied as above would not be as effective as the combination of gelatin + albumen. In my method the primary use of the gelatin is as a carrier to provide a mechanism for applying the albumen in a manner that will permit it to set fairly thick. In other words, in the actual transfer operation the albumen, though only 1/3 as thick as the gelatin, does most of the heavy lifting.

Hope you find this information useful.

Sandy

[koraks]

Oh, this is very useful indeed, thank you so much! Especially the bit where you explain how much sizing you actually use is essential; that sort of information is left out in too many descriptions.

I tried a simplified metal rod sizing approach once, and it made me aware of the mechanical aspects that require nailing down. I've put that in the fridge for now and brush size my papers. It sounds like and gelatin & albumen mixture might be brush coated just as well, although it may require two or more coats to get sufficient thickness and an even sizing. I may try my hand at this. The rod technique sounds superior in that it will lay down a near perfect layer.

Thanks so much!

[sanking]

Mountains vistas are always beautiful, but sometimes disappoint in photographs. I have found this to be especially true in the southern Appalachians mountains in the US, near where I live.

This view did not disappoint. The photograph was made from the top of Wayah Bald, located in the far west of North Carolina, near Franklin. The view is looking toward the south, and much of the view on the horizon would be in Georgia. The top of the mountain is at about 5400 feet.
https://en.wikipedia.org/wiki/Wayah_Bald

I went there last week, before there was any new growth on the trees. Also, there was a major fire there last fall that killed many of the trees you see in the foreground, which left the vista more open than it would have been last year at this time. And the black from the burn on these trees provided a lot of contrast, which made the look very unique compared to what might have been done in the past.

Image capture was with a Sony a7r, converted to IR, and 55mm Grandagon, used on a Cambo Actus with stitching of nine separate shots.
After merging the image size was about 250 MP.

Print is a carbon transfer, image size of 16X23" on Arches Aquarelle cotton rag paper, sized with GAD (gelatin + albumen + dichromate), and hardened by sun. I sized the paper yesterday, and hardened it this morning. Carbon tissue was home made to one of my formulas, 14 grams of Black Cat plus 2 grams of Mixol Violet per liter.

Hope you like it. The combination IR look, of spring foliage at lower elevations, and difference in elevation, plus the spotted clouds, gave a very distinctive look to me. I have lived and photographed in this area for many years, and never made a photograph with this specific kind of look.

What you are looking at is an actual .jpeg of the carbon print, made with a digital camera, with no adjustments of density or contrast.

Sandy

[Erik Larsen]

An interesting take on the scene. The background almost looks like a violent sea. My compliments

[sanking]

The background almost looks like a violent sea.

That is almost exactly what my wife said when I showed her the print!

Thanks,

Sandy

[David Lobato]

Wayah Bald and Ossabaw are beautiful works of art.