The cover illustration for The Alchemist’s Portrait was based on the Portrait of Giovanni Arnolfini and his Wife (1434) by Jan van Eyck.
Another famous painting mentioned in the novel is The Laughing Cavalier by Frans Hals (1624), and the painting entitled Banquet of the Officers of the St Hadrian Civic Guard Company (c. 1627), also by Frans Hals, will give you a good impression of how people dressed in seventeenth century Amsterdam. One of the figures in the painting was also the inspiration for Nicolas van der Leyden, the villain in The Alchemist’s Portrait. You can view more of the work of Frans Hals here at Artsy, where there are also examples of paintings by thousands of other renowned artists. Check out the Artsy website here.
You can check out some of the sources of inspiration for the novel on Pinterest. Here are also some links to sites with more information about the historical periods referred to in the novel.