Christina is an assistant professor of photography at Montana State University, Bozeman, Montana. Her specialties are experimental and alternative processes. She received her undergraduate degrees in French from the University of Minnesota, painting and photography from Montana State University, and an MFA in photography from Clemson University. She has written three books--The Experimental Photography Workbook, Tutti Nudi, Reflections on the Reemergence of the Nude during the Italian Renaissance, and Alternative Processes, Condensed: A Manual of Gum Dichromate and Other Contact Printing Processes. In the works is a book devoted solely to gum printing.
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Ask The Experts
Dear Christina, To print photos on ceramic tiles I have ordered Ag-plus emulsion which I plan to tone with CE-1 toner then fire. My questions are: 1. Do I need to glaze and fire the tiles first? 2. If so, what cone should the glaze be capable of firing to so that it will withstand the second firing with the toned emulsion? 3. Do I need to prepare the glazed surface with gelatin before putting the emulsion on the tiles? Thanks, Robyn
Hi Robyn, I am not a ceramist, therefore not an expert on your question, but I have not heard of firing tiles coated with liquid emulsion. I know that photographic images have been placed on ceramics with dichromated processes, but not liquid emulsion. The ag emulsion is silver in a gelatin base, so whatever will burn off gelatin will burn off the emulsion. From my understanding, it doesn't go through a fire because the burning point of gelatin is very low, but, in fact, is applied to an already fired and glazed tile. The tile must be "subbed" with either a clear polyurethane glossy varnish, or with a gelatin layer. With the latter, use a packet of Knox gelatin in a cup of cold water, let dissolve, then heat to 140 degrees. At that point you have to add a hardener to the gelatin--Freestyle sells Black Magic hardener. This is "loosey-goosey", meaning just add drops of hardener to your gelatin, say, 12 drops to the cup of hot gelatin. Then you want to also add drops of the hardener to your liquid emulsion Ag product--about 5 drops per teaspoon of Ag+ That way your gelatin is hardened and so is your liquid emulsion and upon development they will not "frill" off the tile. Then when the tile is finished the development, fixing, and washing process, spray it with a layer of Krylon Crystal Clear acrylic varnish, or more of the polyeurethane to protect it. I have done both of these methods with tiles. The biggest problem you will encounter is bubbling of the layer off the tile so watch for that. Good luck and treat the tiles as fragile when done.
Hi, I am taking my first photo class at our local college - I LOVE IT! I will be teaching a Kids Artfest this summer, for 1 week. I would like them to build pinhole cameras, but I have no way to develop after. I am now experimenting with Sunprint in the pinhole. Any other ideas? Has anyone tried this? Any other projects for prints that are doable to excite these youngsters? Also does "sunprint" come in a liquid form that could be used on other surfaces, like t-shirts? Thanks so much, Kate M.
Kate, Cyanotype is a wonderful thing to teach a class of young kids. Non toxic and easy. There is a liquid that you can soak paper or even fabric in, and it might be either the Ware's formula cyanotype or the traditional cyanotype solution. Exposing in a pinhole may take a long time because cyanotype is pretty slow--it takes 6 or so minutes out in direct sunlight so in a camera it would be quite long. I suggest you buy the liquid/kit from Freestyle, paint it on your paper, and lay items on top of the paper out in the sun and under glass for a period of time to make photograms. Students get very excited about this. Then develop in plain water until all yellow disappears. Good luck!
Hello Christina, I am a photography student at Pasadena City College in beautiful Southern California and I had a experimental photography question I thought a pro might answer! I am working with liquid light and I can't seem to stick the liquid light to wood. I sanded it and I coated it with glossy polyurethane varnish and it does not seem to work. Do you have any methods i could use to help me with this or should I just switch to a different surface altogether? Your help is surely appreciated! Sincerly, Daniel
Hi Daniel, A glossy polyeurethane varnish should be just fine for a sub. However, you probably need to add a hardener such as Black Magic Hardener to the liquid emulsion. Sanding also helps. Try the hardener, but in general, wood is tricky as a substrate. Remember your highlights will only be as light as the wood so it usually prints a fairly dark image. Good luck,
Hi Christina, I am working on a camera-less photo project. I need to expose a large - 8' x 6' sheet of non-photographic paper to the sun during the very early morning hours (5:30am-8:30am). I need to coat this paper with some sort of emulsion or light sensitive chemical. The catch is that the final image must be Black and White - so I can't use Van dyke or Cyanotype. I will be cutting a paper template to put over the paper so only certain areas are exposed to the sun. Can you recommend a user friendly process that doesn't involve much experience and is relatively inexpensive? Thanks so much for your speedy response (i need to figure this out soon as its in conjunction with the coming Solar Eclipse on August 1st). Luke
Hi Luke, You could certainly do salt printing or POP (Printing Out Paper) but the color will be reddish brown. It does use silver nitrate, though, so it is technically a silver process. However, if the image needs to be literally B&W the only recourse I can think is to get Liquid Emulsion, coat it on in the dark, and then expose it. It is the speed of a normal B&W paper so you will definitely have to do test strips to see how long to expose it before you sacrifice a huge piece of paper. Then, you will have to develop a system of developing and fixing for a large piece like that, that allows you to roll and do a thorough soaking job or else you will get major brown spots and it will smell like fish. I am concerned, also, about your exposure time. Since paper can be about an ISO of 6 (and remember, you'll be getting a negative, not a positive image) you'll have to figure a very long exposure. BUT, the good thing is paper does not experience reciprocity failure as bad as film. Test strip!! Good luck with your project!
Ferric Ammonium Citrate has shelf life that I know of; Someone just said they used 25 yr old stuff and it was as good as new!
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