[1] The base of the jar is emblazoned with the reign mark Da Ming Jiajing nianzhi, or "Made during the Jiajing reign of the great Ming dynasty," in two columns, but the distinctive style would have made the time period clear enough without that label.

For the first firing, a clear glaze over a cobalt-based paint resulted in vivid blue designs on the white porcelain.

Before the second firing, translucent enamels applied over the glaze resulted in a range of brilliant colors.

The end result is this vivid design, the swimming carp depicted from an angle that makes it appear the jar is transparent.

[1] Since Jiajing was a devout Taoist, motifs popular in that tradition became widespread during his reign.