Slip-painted ceramics: engobe decor, feathering, firing

I decorate raw pots with coloured clays while the body is still damp — leather-hard, and sometimes a shade softer than that. Timing is the whole craft here: too wet and the wall slumps under the brush, too dry and the slip lifts off in flakes after the first firing. The engobes I use are milled from the same clays as the body itself, refined and tinted with oxides and stains, so they shrink together with the pot instead of fighting it. That is also why I ask what form you want painted before I mix anything: a tall jug and a flat plate lose their water at different speeds, and the decoration has to be planned around that.

The marks themselves come from three tools, often on one piece. A rubber bulb lays down fat, even ribbons and solid grounds; a soft brush gives the loose strokes, the dots and the running grasses along a rim; a slip trailer with a fine quill draws the thin, even line that holds a pattern together. While the slips are still wet I comb across them with a notched stick — feathering — and the parallel bands break into chevrons, feathers and marbled swirls. That step tolerates no pauses: the piece is finished in one go. Where I want a drawing rather than a flow, I let the coat set and scratch through it with a needle, so the darker body shows under the lighter coat. That is sgraffito, and it is slow work — an average plate takes an evening.

After the decoration dries the piece goes through a biscuit firing, then takes a clear glaze and a second, glost firing to the full schedule. Anything meant for food is covered with a food-safe clear glaze free of lead and other harmful additives, so it can be eaten from every day and washed in a machine. Expect the colours to come out deeper and warmer than they looked on the raw clay: iron slips drop a couple of tones in the kiln. For that reason I fire a test tile in your palette before any series, and you approve the fired colour rather than the wet one.

What is included:
— a sketch of the pattern for your form and a short talk about the palette;
— a fired test tile in the agreed colours before the series starts;
— painting in slips: poured grounds, brushwork, trailed line, feathering, sgraffito where asked;
— biscuit firing, clear food-safe glaze, glost firing;
— careful packing and a written note on care.

I take orders for single pieces and for sets — from a pair of mugs to a service for twelve. For a series I plan the time around drying and two kiln loads, so ten days is a realistic turnaround for a small set; a large one is agreed separately.