Miniature Portrait of an Unknown Sitter by Solomon PolackOil miniature on ivory of an unknown sitter, signed 'S. Polack.' Solomon Polack (1757-1839) was a Jewish artist born in The Hague who worked in Dublin and London from 1790 to 1835. He frequently exhibited at the Royal Academy and, in addition to miniature painting, designed and etched plates for a Hebrew Bible.