Quadraturist

When the two friends were engaged in decorating the archiepiscopal palace at Ravenna, and at the courts of Parma and Modena, Mitelli alternately assisted the figurist and the quadraturist.

Source: wiktionary

Agostino Mitelli also worked with them as both figurist and quadraturist. Colonna, however, was an extremely capable quadraturist, and he became so specialised that he soon left Il Dentone's studio, setting himself up independently. It is not a simple task to distinguish which of the two artists painted ceilings or walls in the Rooms, or to whom the activity of figurist or quadraturist should be attributed.

Source: wiktionary

He had worked with the Bolognese quadraturist Antonio Maria Bernardi, who had served Max Emmanuel at Schloss Lustheim (the hunting lodge connected with Schleissheim) from 1688 to 1689.

Source: wiktionary