The last few years have seen a surge in the development of online catalogues raisonnés, in which the complete works of an artist are meticulously documented. Over the last five years or so, Walter Feilchenfeldt, Jayne Warman, David Nash and others have been working on that for Paul Cézanne. It is now complete, and available to access here.

This covers all Cézanne’s known oil paintings, watercolours, drawings and sketchbooks, making it uniquely comprehensive.

Users do have to register to access it, but for non-commercial use it is completely free of charge. Compared to the cost of the recent multi-volume catalogue raisonné of John Singer Sargent, for example, it is an extraordinary resource. Much as I love beautifully-produced books, owning and accessing printed reference works is prohibitively expensive for most people, and well-designed online sources like this are far more powerful to use.

For example, when checking details for the caption to a painting by Cézanne, I can do this in a minute or two through the online catalogue raisonné, but checking in its printed predecessor would take me ten or fifteen minutes. The online successor can also be kept constantly up to date, rather than frozen at the date of publication and thereafter growing ever more inaccurate.

We should all be very grateful to those who have contributed to this, including the International Music and Art Foundation who provided financial support.