How a blue-and-white vase is painted

In a studio on the east bank of the Chang River, a painter loads a brush with cobalt oxide and holds her breath. The vase in front of her is bone-dry but unfired — what the Chinese call bisque. One slip of the wrist, and the line she's about to draw cannot be undone.

Blue-and-white porcelain looks simple from a distance: white body, blue painting, clear glaze. The process of getting there is anything but. This piece walks through what actually happens between a thrown vessel and a finished, glazed vase.

The body must be right first

Painting begins only after the thrown form has been trimmed, dried, and biscuit-fired to around 900°C. At this stage the clay is porous but stable. It absorbs moisture quickly, which means the painter cannot hesitate — a brush held too long in one spot bleeds into the body.

The best porcelain bodies for blue-and-white are high in kaolin and petuntse, the two stones that give Jingdezhen ware its characteristic translucency after a high reduction firing.

Outlining: the first brush

Cobalt oxide mixed with water and a small amount of organic binder forms the paint. The outlining brush is fine-tipped and loaded lightly. The painter draws the entire composition in outline first — landscape, figures, borders — without filling anything in.

"The outline is the bones. The wash is the flesh. You cannot fix a weak bone with beautiful flesh."

This is the stage where irreversibility matters most. Cobalt on biscuit cannot be fully washed off; dampening and scraping leaves a ghost that will show through the glaze.

Washing: building depth

After the outline dries, a second, broader brush is used to lay in washes of varying cobalt concentration. Darker areas — folded fabric, deep water, dense foliage — get a heavier load. Lighter areas get cobalt diluted with water.

The painter works quickly because the biscuit body pulls moisture down. A wash that looks dark when wet will fire substantially lighter; judging the final tone requires experience with the specific kiln and clay body.

Glazing and firing

Once the painting is complete, the piece is dipped in or sprayed with a clear glaze. The cobalt is now completely covered — the painter cannot see the true blue until the kiln opens. Fired in a reduction atmosphere at around 1300°C, the cobalt reacts to produce that characteristic deep, slightly violet blue.

What comes out is never exactly what went in. That unpredictability is not a flaw in the process. It is the reason every hand-painted piece is irreproducible — and why the process has survived seven hundred years.