While a variety of surfaces can be coated various emulsions, paper is the most widely used for most processes and the most preferred.
The best papers for coating will be those that are not too soft and have been sized. Working with paper and processes that do not require highly sized paper makes working much easier.
Unsized papers will soak the sensitizing solution too deeply and unevenly into the paper. (If you wish to experiment with softer papers, you may need to size them with gelatin before coating them.) Use any paper that can stand soaking, such as many watercolor, etching, and charcoal papers, commercial offset cover stock, or heavier sketchbook pages. Clobbered papers may bleed or fade. Any paper can be coated with an emulsion but there is great variation in both the and physical strength of papers, and many are not suitable for coating.
Recommended papers that need no size
Lana Royal, Crane’s Kid Finish, hot pressed Arches or hot pressed Strathmore watercolor paper.
Two papers recommended for hand made emulsions are Arches and Rives BKF, but may require sizing.
For the Arcane project Tess Edwards and my self used Canson drawing paper 220 gram acid free.
Paper strength
It should be remembered that any paper or support base is not only coated with the liquid emulsion but processed in liquid and needs to be strong enough to withstand this processing and washing. I have seen artists coat a thin piece of tissue paper with emulsion and then watch as it disintegrated during the processing. If you are unsure about a paper, test a small paper sample by soaking it in water at least an hour, or overnight, then pick it up and turn it over several times. If it tears easily or falls apart, it is unsuitable. Although the quality of paper differs greatly, the thickness of the paper gives some indication of strength. I have found 220grm paper very effective.
Using soft papers
Often it is not the construction of the paper but the weight and handling when wet that destroys it. A method where finer and softer papers can be taped down onto a board to coat expose and process it can be useful in retaining the sheet intact. (Use wettable package tape for this). If you don’t want to introduce acid or contaminate the paper the board should be coated with sanding sealer or polyurethane varnish. Remember that if the paper is taped down this edge will be lost when the print is cut off the board.
pH value of paper
The pH value of the paper and other additives in any paper determines stability of the paper over time. Papers with a low acidity will last a much longer time than papers with a high acidity.The purest papers are referred to as having a pH of 7 which is designated as neutral and the same as water. Using papers or materials with a higher acidity means they will react over time. Paper surface: Papers come in a range of surfaces which can be incorporated as part of the aesthetics or concept of the work, and generally course textured papers diffuse the detail of the image while smooth surfaced papers give the maximum sharpness and increase contrast.
Paper surface
Papers come in a range of surfaces which can be incorporated as part of the aesthetics or concept of the work, and generally course textured papers diffuse the detail of the image while smooth surfaced papers give the maximum sharpness and increase contrast.
Storage
It is wise to store any work on paper with care. Dust and dirt that collects on paper left out for a length of time, this in turn collects moisture and can transfer acid onto the paper. Keep unframed finished works, or uncoated and processed paper wrapped in acid free tissue paper and stored in a suitable plastic bag.