According to the Netherlands Institute for Art History (RKD), he was the son of Herman van der Mijn and was born when his father moved to Düsseldorf to work for Johann Wilhelm, Elector Palatine.
[1] In 1750, Johan van Gool wrote about him, his father, his brothers Robert, George, Andreas and Gerard, and his sister Cornelia who were all good painters.
He had considerable merit as an artist, but was of mean address and vulgar manners: He loved smoking and drinking, nor would forego his pipe, though it was offensive to his employers, so that he never acquired the practice which he might otherwise have obtained.
He boasted, that after he had painted a portrait, the likeness remained so strong upon his memory, that if the picture were immediately obliterated, he could repaint the resemblance without the assistance of the sitter.
The wife of one of them was also of the profession: She painted fruit and flowers, and they were all exhibitors at the Society's Rooms in the Strand, in the years 1761 and 1762.