Custom porcelain: slip casting, high firing, decal and gilt rim

I cast porcelain the slow way, and I start with a model rather than with the mould. A turned master is where the profile of the future piece is decided: the line of the foot, the thickness of the lip, the angle at which a handle leaves the wall. The master is made oversize on purpose, because porcelain loses up to fifteen per cent of its size between the wet wall and the finished cup. A rim that has to sit inside a lid or match a saucer is therefore calculated three steps earlier, on paper, before a single gram of plaster is mixed. Only then do I cut the case and pour the working mould, in two or three parts, keyed so the halves close without a step.

Casting itself is a matter of minutes and of watching the clock. Deflocculated slip goes into a dry mould, the plaster draws water out of it, and a wall builds against the inner surface at roughly a millimetre every eight to twelve minutes for the body I use. When the thickness is right for the object I drain the surplus, let the piece stiffen until it releases from the plaster by itself, and only then open the mould. After that comes slow drying out of any draught, and fettling: the seams are cut back with a blade and smoothed with a damp sponge until the join cannot be found by fingertip. A seam left proud will show through the glaze as a ridge of light, and no decoration hides it.

The bisque firing runs to about 950 °C. The ware is then glazed and taken to a high firing of 1280-1320 °C, where a thin wall becomes genuinely mobile. Tall and wide forms go onto fitted refractory setters and rings so that the rim leaves the kiln round rather than oval, and plates are supported across the whole foot. Decoration is overglaze: the decal is floated onto the glazed surface and squeegeed free of water and air, the rim is lined with real gold by hand on a turntable, and a third firing at 780-840 °C fuses both into the glaze. Gilding of this kind is durable but not indestructible, so I ask for gilded pieces to be washed by hand; plain glazed ware takes a dishwasher on a normal cycle without trouble.

What the work includes:
— drawings and a master model with the shrinkage allowance calculated for the body;
— a multi-part working plaster mould, keyed and numbered, kept for repeat runs;
— casting, drying, fettling and sponging of every piece;
— bisque firing, glazing and high firing on supports fitted to the form;
— overglaze decal to your artwork and a hand-lined gold rim with a third firing;
— a sample piece for approval before the run, and photographs of the finished batch.

Runs from a single piece to several hundred. A first sample normally takes two to three weeks because the mould has to be made and dried; repeat orders from an existing mould are much faster, and I keep moulds in the workshop for as long as they cast cleanly.