[2] The early Flemish biographer Karel van Mander reported in his Schilder-boeck (1604) that de Backer was abandoned as a young boy by his father, also a painter, who had to flee Antwerp because of an impending court trial.
He then worked for a number of years in the studio of a painter and picture dealer of Italian origin but Protestant confession known as Antonio van Palermo (1503/13–before 1589).
Van Mander claimed that Palermo worked him so hard that the young de Backer died in the arms of his master's daughter at the age of thirty.
While his work shows a strong influence of the Mannerism of Rome and Florence, in particular the high Mannerist style of Giorgio Vasari, there is no evidence that de Backer made a study trip to Italy as did many of his contemporary Flemish artists.
None of his pictures mentioned by Karel van Mander in the Schilder-Boeck have been securely identified and no painting or drawing attributed to him carries a signature that can be authenticated.
[1] Only three known pictures can be traced back by means of provenance to the days of de Backer and serve as the basis for the attribution of "other, undocumented paintings".
The difficulty of a clear provenance and definition of the artist's style has not stopped the art trade from attributing a large number of paintings and drawings to de Backer.
The works attributed on these grounds to Jacob de Backer exhibit wide differences in artistic quality and represent a plurality of individual sub-styles.