When Durer opened his workshop in Nuremberg in 1495,  at the age of twenty-four and relatively few commissions for paintings came his way, he was easily able, with the assistance of his godfather, the highly experienced publisher Anton Koberger, to set himself up as a print maker producing woodcuts and engravings.  These were the main source of his income, Although he regularly carried out individual commissions for paintings and occasionally prints, he profited most from the producing prints for an open market. In August 1509, he complained in a letter to the wealthy Frankfurt cloth merchant, Jacob Heller, for whom he had just taken over a year to paint an altarpiece, that if he had stuck to producing prints he would have been considerably better off.  Giulia Bartrum p. 10