His animal studies were used as models for the animals appearing in the borders and foreground of a series of large tapestries, referred to as 'The Months' or 'The Royal Houses' (Maisons Royales) produced at the Gobelins tapestry workshop. Each of the tapestries represents a different royal residence. Conscious of the value of Boel's animal repertoire, the Gobelins workshop kept the entire set of Boel's painted and drawn studies numbering 81 in total. They represent mammals, birds, a tortoise, a lobster and a lizard. They are painted against a red or pink background. He painted the fur, plumage, paws and eyes of the animals with a free brush. The same animal is in some studies represented in different positions. The species are mixed in studies, but it is rare for furry animals and animals with plumage to be included in the same study. The French painter François Desportes copied several of his paintings and as a result, it was believed that the original drawings were by Desportes. It is only after it was confirmed that the originals had been made by Boel that Boel's reputation as an animal painter was re-established. Charles Le Brun used Boel's studies for his own works.