Brolliet's method of overglaze hot press printing with oil

Brolliet’s Method of Overglaze Printing by Hot Press

The difference from Spode’s ‘Pluck and Dust’ printing is that in Brolliet’s method the design printed in oil on the tissue paper has the pigment dusted on to it before the design is transferred to the pot. It seems likely that Brolliet learned this method from his fellow-countryman the engraver Ravenet, who had been involved in printing at the Battersea enamel factory. For the evidence click here. It is possible that this method was used to print saltglazed stoneware plates at Battersea. Click here for Brolliet’s original account in English translation or in the original French.

Stage 1: engraving or etching the copper plate
The first stage was to engrave the design into the surface of a copper plate. Engraving means cutting into the metal with a sharp steel tool called a burin. Sometimes the plate was etched as well as engraved. Etching uses acid to bite into the surface of the copper. The plate is first coated with a wax which protects it from the acid and is known as a ‘resist.’ The design is then lightly scratched through the wax. The plate is then exposed to the acid. The acid bites into the copper wherever the design has been scratched through the wax. The result of both engraving and etching is a plate with the design cut into its surface.

Stage 2: transferring the design from the copper plate to the tissue paper
The printer heated the copper plate and rubbed fine oil with just a trace of pigment into the engraved lines. Heating the plate made the mixture run better into the lines. The printer carefully wiped the mixture off the surface of the plate, leaving it only in the lines. The printer then placed a dampened sheet of tissue paper on the plate and passed the two together through a hand-printing press. This transferred the oil from the copper plate to the tissue paper. The paper was then carefully peeled off.

Stage 3: transferring the design from the tissue paper to the pot
Powdered pigment was then lightly dusted on to the paper. The pigment stuck only to the parts that were oiled. The paper was then placed on the pot and rubbed to transfer the design on to it.

Stage 4: fixing the print on the pot
The pot had already been dipped in glaze and then fired before the print was applied, so this was an overglaze print. It was fixed by firing at about 750 degrees Celsius, a lower temperature than that of the glaze firing, which was at least 1000 degrees Celsius. The print was therefore less firmly fixed than the glaze below it and might be damaged by wear over time.