I decided I wanted this pagoda design on the current sculpture set I'm working on, but the pieces have already been bisqued. The base clay is Bmix and sand, and I've applied a white slip over it in the green stage.
Tracing of pagoda design onto bisqued piece with graphite paper.
Originally, I was thinking of doing a wax resist or a stencil treatment with the design. I opted for the dimensional effect I was able to achieve with my "Take Out Tea" sculpture.
The paperclay slip I use is the Southern Ice Porcelain paperclay. The slip is consistency of heavy cream and blended well to remove lumps. I use a squeeze bottle with a small nozzle - the ones you use to do slip trailing. The design is first transfered on to the bisqued piece and the slip trailing is done free hand. Successive coats are built up to achieve the desired raised effect. Since slip is mostly water, it takes several coats to accomplish this.
What I found is that if my slip is too thick, the edges then to curl and peel from the bisqued surface. Wetting it down with a fine mist from a spray bottle helps. What works better is thinning out the paperclay slip till it's about skim milk consistency and then brushing over the design with a small brush. This thin slip still contains the paper fibers in suspension and this helps to "hold" your relief design in place. Both bisqued piece and the fresh dry slip being very "thirsty" sucks the moisture out of this this watery slip extremely fast. So far, my design has not exhibited curling or peeling at the edges.
After several applications of fresh slip. You can still see the tracing of the pagoda under the slip.
The next stage is to test this application by re-firing the piece at bisque temp and see if this holds.
After the bisque firing, my added on design held and bonded with the base layer, showing no signs of cracking or lifting off. This is very encouraging!
After the bisque firing, the graphite tracing burns off. The freshly applied paperclay slip is bonded onto the piece.