Adding paper pulp and other fibers can make things you never thought possible with clay totally doable. Combining the fibers with clay reduce shrinkage in the drying stage and strengthen joints, allowing wet and dry pieces to be joined.
In today’s post, an excerpt from Additions to Clay Bodies, Kathleen Standen explains the ins and outs of the remarkable combination of clay and paper. – Jennifer Harnetty, editor.
Strengthening Your Clay
by Kathleen Standen
The most commonly used fibre is cellulose, made from paper pulp. Ceramicists generally have a favorite paper they use, such as newspaper, egg cartons or toilet paper. The proportion of clay slip to paper pulp varies, but a typical sample would be 4:1. The clay slip and paper pulp are mixed thoroughly together, with the best results achieved using a blender or electric mixer. The blended mixture is then laid out on plaster batts to dry a little so it can be wedged into balls of clay. The proportions can vary from 5% to 25%; carrying out your own investigations is the best way to find out what suits your work.
Adding materials to your clay can change the look of your surfaces and produce a wide variety of textures and shapes. Kathleen Standen takes a look at all the possibilities in her book Additions to Clay Bodies where you’ll discover how adding non-clay materials to your clay provides a great way to be creative in a whole new way.
The shelf life of homemade paperclay is about two weeks, so it needs to be used up quickly; if kept for longer, the organic cellulose starts to break down and decay, with all the health issues explained in Chapter 3 (p. 46).
When paperclay decays, the tubular structure of the cellulose fibers breaks down and the paperclay loses the properties associated with it; toilet paper is more prone to rapid decay because of a corn-starch coating on the cellulose fibers.
The usability of paperclay can be extended by adding a small amount of Milton sterilizing liquid or disinfectant (but not bleach) to the wet mixture before drying.
Alternatively, rolling out unused paperclay into thin sheets and allowing them to dry completely preserves the tubular structure of the fibers. They can be stored, and later softened up by laying them out on a damp cloth.
Cotton Fiber and Clay
An excellent alternative to paper pulp is the addition of cotton fibers. This can be purchased in sheets as cotton linter. Preparation of the materials is the same as for paper but cotton fibers don’t break down as easily as paper, so it can be stored in its wet form for longer. If you don’t want all this hassle, then the pottery suppliers listed at the back of the Additions to Clay Bodies will sell you a ready-made paperclay with an unlimited shelf life (as long as it is wrapped up well).
Paper Fibers, Perlite and Clay
Barbro Aberg’s large-scale sculptures are not easily categorized. As a Swede living in Denmark, combined with a five-year stint in the US, she has developed her own distinctive style. She exhibits her ceramics in galleries and events throughout Europe and the US.
She was introduced to additions early on: to perlite by US artist Bob Shay and paperclay by Rosette Gault. Testing of several different mixtures followed, until she found the correct formulae to suit her way of working. “During the years, I have developed several specific clay bodies: one for large, solid work, one for small pieces and one for open structures,” Aberg says. “They give me a range of possibilities for working freely with my sculptures.”
Most of her ceramics are modeled by hand, a slow process that allows Aberg to change the form as she constructs it. Larger pieces can take 6-7 weeks to finish. “I allow myself to reflect, alter and change, follow the impulses that emerge, and give room for a dialogue with each sculpture.” The work is fired to
1135-1140˚C (2075-2084˚F) in an electric kiln, often more than twice, or until the right surface is achieved. Terra sigillata is sometimes applied to the surface.
Get to know clay better by downloading your free copy of Successful Tips for Buying and Using Pottery Clay: How to Select, Process,and Test Clay Bodies for Better Results.