Fantastic Figures: Ideas and Techniques Using the New Clays. The following applies most specifically to Creative Paperclay, but the basic techniques and effects are essentially the same for all air-dry clay products.
"Creative Paperclay is basically water, paper pulp, talc,
starch, and volcanic ash, with preservatives to keep moisture from causing mildew. It dries in open air and is extremely strong, even in small, thin areas.... Composed of pulp fibers, when sculpted the fibers overlap, creating an almost woven structure."
"Just because paperclay tends to dry once it is out of the package does not mean you have to work fast. You can keep work in process for days and weeks if you keep it damp while you are working and cover it well when you are not. Usually, a tight cover of plastic wrap or a thin plastic bag will keep a piece moist for a day or two. Check and spray with water if necessary after no more than two days." (An alternative approach is to build the paperclay sculpture over the armature very slowing, letting each layer dry before you add the next.)
"When your piece is ready for final drying, remember that paperclay pieces can warp while drying. This is not necessarily due to the material itself; often it is the result of span, gravity, and uneven downward pressure or weight that the piece exerts on itself. If a leg is laid on its side with no support, an ankle could bend out of the sculpted line. The same is possible with parts like arms, wrists, and breastplates. You will need to consider this and prop pieces wherever they could sag."
"Paperclay can be dried in open air on a wire rack. The process can be speeded up by using a fan, drying outside when temperatures are above 70 degrees F with low humidity, or drying in a warm oven. When oven-drying, leave the door open so that moisture can escape."
"Whichever method you choose, the piece is dry when it feels dry, is not cold, is almost as light as Styrofoam, and is white. Remember: warm, light, and white."
"Sagging or cracking that might occur during drying can be easily corrected. If a large area needs to be fixed, rough up the surface with sandpaper and a file, moisten, and add wet paperclay. If a crack occurs, mix paperclay with water to a paste and fill in. Breakage is rare; dry paperclay is extremely strong, even in thin areas. Small fingertips can break off, but only under considerable force. A clean break can usually be repaired more efficiently with craft or wood glue than by trying to re-build the area with paperclay."
"When dried, it can be sanded very smoothly or re-sculpted by carving or addition. No material is totally perfect, however. Paperclay is a wet product. That means that, unless sealed, it can become soggy when exposed to damp conditions."
Many different products can be used to seal air-dry clay...and that will be a topic for another day! Do you have any drying/curing tips to share?
Susanna Oroyan was a master doll maker and book author. In her many books about doll crafting, she shows every step along the way to making any kind of doll you can imagine. Fantastic Figures deals with clay sculpting of dolls and every aspect of it-from the head to the feet.