The online catalogue is based on the author's "Honig Database" (compiled from 2000-2010), which includes the over 560 paintings listed in Klaus Ertz's 1979 catalogue (see entry in this database), as well as verified works from the art market and elsewhere that have appeared in the interim. Hundreds of copies and variants after Jan Bruegel's works are also listed. The online corpus lists over 750 paintings and more than 350 drawings, as well as some oil sketches and prints. Additional online catalogues for other Brueghel family members are planned.