When we ran a couple of features recently on using paper clay (see “Paper, Clay, Steel: Combining Disparate Materials to Create Strong, Lightweight Ceramic Sculptures” and “Lose Weight, Get Strong: Put Your Ceramic Work on the Paper Clay Diet”), I received some emails from readers asking for more, more, more! Many were interested in more basic information on the process. So today, I am going to fulfill those requests with a post by one of the foremost authorities on paper clay, Rosette Gault. In this post, Rosette explains some basics of paper clay preparation and takes you through the process with some step-by-step photographs. Plus she gives some health and safety tips for working with paper clay. – Jennifer Harnetty, editor.
Tips on how to select and evaluate the types of paper to use
Lower-grade paper, such as shredded paper from copying machines, works very well. Even yellow- or pink-colored papers do not adversely affect the mix. Fired results of lower-grade paper are relatively more dense and slightly heavier than with higher grade. Toilet paper (bathroom tissue) is also a good source.
Certain types of better stationery and/or brochures or leaflets printed on nonglossy paper are among the higher grade papers. Higher “rag” content means more delicate fibers.
Don’t use newsprint, brown bags or cardboard if you want a clean, white result. There is too much sawdust-grade pulp in their compositions. Glossy brochures and catalogs take a longer time to break down into pulp so they should be avoided.
Use a consistent source for your paper. Once you’ve selected a paper, make a test batch of clay and test fire it to be sure that you like the clay color. Most inks, including those used in photocopiers, are carbon based and burn out during firing; but ink-containing mineral oxides will stain your clay. Testing also helps determine the best proportion of paper to clay for your purposes.
Wet clay particles are much smaller than paper fibers so they mold to the fibers as they dry. When the paper burns away during firing, a fine-grained lattice-like structure results.
Be aware that adding paper to your clay body may significantly change the maturation temperature, because small amounts of clay are routinely added to commercial papers to improve texture, and the clay in your pulp will tend to raise overall maturation temperature.
Turning paper into pulp is simple. For already shredded paper, use a large, watertight barrel. Fill it halfway with the dry, spaghetti-like shreds.
Pour in clear water, enough to fully saturate each piece of paper. Hot water seems to speed this. Soak as desired.
For papers/brochures that have not been shredded, fill the watertight barrel a third of the way with clean water, hot if possible. Tear the paper into 3-4-inch scraps. Drop each scrap into the water. The wet paper will start to disintegrate and expand. Some papers are so absorbent they grow like sponges to five or six times their original volume.
Once the paper scraps are thoroughly saturated, use a glaze-mixing blunger to homogenize.Be generous with the water in pulping and add water if the mixture is too thick; it should be very soupy so as not to overtax your mixer. Add a few drops of bleach to retard mildew and bacteria growth, especially if you don’t plan to use the pulp within a day or two.Mix the slurry until the printing is illegible and the pulp appears to be homogenous.To drain, pour the slurry over a large-mesh screen, and press the water out by hand. Strain the pulp gently.Squeeze out as much excess water as possible. Store the mostly de-watered pulp in an airtight plastic bag until you are ready to mix it into clay slip.However, do not let this wet pulp sit for more than two weeks or it will smell worse than a garbage dump. To store the pulp so it won’t rot, you can freeze it in convenient packages. A better way, however, is to allow unused pulp to dry out, then reconstitute what you need in water.
Health and Safety with Paper Clay
- If you have any skin sensitivities or skin allergies, wear rubber gloves when handling paper clay.
- If you batch any dry powder materials, be sure to wear an approved respirator.
- When blunging the clay, wear goggles.
- Due to the wide variety of potential ingredients found in clays, papers and waters in various regions of the world that are beyond the control of the authors and the publishers, use caution and care in trying these methods.