The catalogue is divided into three sections: Paintings, Watercolors & Drawings and Sketchbooks.The first two sections are subdivided by groups or themes; the sketchbooks are treated separately, each with its own master number and individual sheets linked to it.
The Paintings section begins with FWN 1, Watercolors & Drawings begin with FWN 1000 and the Sketchbooks with FWN 3000.
The entire catalogue can be sorted by FWN number, date, or size. Sorting the entire catalogue by date will integrate the works chronologically, however, the numbers will not be consecutive. Filters provide an option to assemble a group of works and to exclude irrelevant ones.
The Search box here allows the user to find a work by FWN, Rewald, Chappuis, or Venturi number, Title or partial title or keyword.
The letters "TA" after the catalogue number indicate that the work has been traditionally attributed to the artist, but has not been physically examined by the authors and therefore its authenticity cannot be confirmed. Several works that are new and unseen or that require further study are also included in this category.