Photogenic Drawing/ Salted Paper

In 1833 William Henry Fox Talbot was the first to create a silver image on paper. He originally used this process to create photogenic drawings. Photogenic drawings are contact prints created by placing an object on top of sensitized paper and exposed in the sun. Anna Atkins, an English botanist and photographer who learned directly from William Fox Talbot, used the cyanotype process to create photogenic drawings that catalogued British plants, such as the one below.

Anna Atkins Cyanotype photogenic drawing (not salted paper print)

Talbot achieved a faint image by applying a sliver nitrate solution to paper, however when he pre-coated the paper with a salt solution the image was much stronger. This process is a printing-out process, this means it requires no chemical developing and the image is completely formed during exposure. Talbot used this process to create the calotype, paper negatives were created by placed salted paper in a camera (example below). These were criticized for their grainy appearance and long exposure times, but were used because it was the only method to create multiple prints from a negative until the wet plate process was invented.

William Fox Talbot. The Open Door. 1843. Salted paper print from calotype negative

Here are some useful links for salted paper prints and more examples of the process.

http://www.alternativephotography.com/wp/processes/saltprints/a-dash-of-salt

http://albumen.conservation-us.org/library/monographs/reilly/chap3.html

http://books.google.com/books?id=6HECAAAAYAAJ&printsec=frontcover&dq=photography&hl=en&ei=2wu3TcDoJMaSgQe_xYGCAQ&sa=X&oi=book_result&ct=result&resnum=1&ved=0CGcQ6AEwAA#v=onepage&q&f=false

The process is quite simple. You start by mixing the two solutions: salt solution and silver solution. Add 2 grams of sodium chloride (salt) to 100mL of water and stir to create the 2% salt solution. Next add 12 grams of silver nitrate to 100mL of water and stir to create 12% silver solution. It is important to where protective equipment such as safety goggles, gloves, and a lab coat when mixing and handling the silver solution because it can cause damage to your eyes, skin, and clothes.

After the solutions are prepared you can begin to coat your paper of choice. Some papers are better than others but most papers will work. I have found that 100% rag paper works best. In the Philosophical Magazine that Talbot published he suggests using a good firm quality paper with a smooth surface. Use a brush to apply one coat of salt solution to your paper. Use even brush strokes and be careful not to overwork the paper. Dry the paper before applying any more coats. You can let the paper air dry or use an electric air dryer to hasten the process. Once the paper is dry apply the first coat of silver solution. Dry the paper and apply the second coat brushing perpendicular to the direction the first coat was applied.

After the paper is dry you can place your objects on top of the paper and set it in the sunlight to create a photogenic drawing. In my experience the exposure should take anywhere up to 10 minutes depending on how sunny it is. According to a photography manual written by Robert Hunt and Francis Peabody in , Talbots exposures were only a few seconds, and his fastest exposure was only half a second with the help of full sunshine.

Although there is no developer in this printing-out process it does require a fixer, a solution of thiosulfate (hypo) can be used. The fixing process will bleach the image to an extent, to avoid this being a problem you should expose the image to be slightly darker than you think is appropriate. First rinse your print in a bath of water for a few minutes then transfer it into the hypo bath for another few minutes. Then wash the prints in water again for at least an hour and hang them to dry.

My experience of this process was positive. We coated the papers well and quickly. The only difficulty we had was the paper began exposing during the coating process so we did not get bright highlights. This process is fast and easy so I can see why it was used to make quick, accurate representations of objects.

We tested solid objects, a semi-transparent object, and transparent color filters.

Below are pictures of our process and results.

As you can see, the blue filter (on top) is darkest. This means that this process is most sensitive to the blue wavelength of light, since the blue filter blocks other wavelengths. The red and yellow squares are close in darkness, however the yellow is slightly lighter (on bottom). This process is least sensitive to yellow light.

The warm tone of the images is obvious. This is a result of the small particle size of the silver. The silver particles are only 10-20nm, which scatters blue light and transmits yellow light.

The image tone is changed upon fixing with hypo. This is because hypo removes silver chloride from the matrix and lowers the refractive index. The lower refractive index will change the absorbtion band to lower wavelengths.

The salted paper process was the first step towards making negatives, which would allow for the reproduction of photographs and the ability to include photographs in books and newspapers. Although salted paper prints produced a gritty image, they inspired others to pursue a better method to create negatives. George Eastman gained his success by creating a flexible transparent film that was better than paper. Talbot laid the foundation of photography as we know it.