For requests regarding works of Cézanne, Van Gogh and Kokoschka please write to:

  • Please send me a photograph of the work (in colour if possible), which I will keep in my archive.
  • Unless further examinations are required, the evaluation is free of charge.
  • You will receive a reply as quickly as possible, which will be accompanied by the remark, “in my opinion,” to indicate that I do not consider my verdict to be absolute; however, this will not prevent me from making my evaluation “to the best of my knowledge and ability”.

Please note the following:

Of course an art dealer is expected to vouch for the authenticity of the artworks he is selling. However, as the market prices for art have exploded, the status of the art expert has attained a significance that exceeds the responsibilities of the ordinary art dealer by far. 

In the course of the gradual publication of oeuvre catalogues of important artists of the past centuries, we have come to think that for each artist there is one expert to decide on the authenticity of works proposed to him. The auction houses present the unregistered works to the relevant experts and sell them – if the result is positive – as an authentic work, that a) will be included in the forthcoming catalogue raisonné, b) that will be included in a supplement to any existing catalogue raisonné, or c) that it is accompanied with the expert’s certificate of authenticity. Furthermore there are cases when a work, registered in the existing catalogue raisonné, is not excepted by the experts as authentic. 

However, experts are only human and consequently can be mistaken. Max Liebermann made the famous remark, that it is the art–historians’ task to declare our bad paintings as fakes . It would take us too far afield to list all the criteria that must be considered before a serious expert may call a work of art a fake. Even more complex are the criteria and the consequences when a completely unknown work comes to be acknowledged as authentic.
The responsibility for authenticity questions regarding the work of Paul Cézanne are shared by Walter Feilchenfeldt, Jayne Warman and David Nash, who are in the process of completing the Cézanne online catalogue raisonné: The work on the paintings has been completed. The website on the works on paper should be finished by the end of 2018.

The responsibility for authenticity questions regarding the work of Oskar Kokoschka is with the Fondation Oskar Kokoschka, which has commissioned Katharina Erling and Walter Feilchenfeldt to complete an online catalogue raisonné of the paintings. This online catalogue was launched end of September 2017:

The responsibility for authenticity questions regarding the work of Vincent van Gogh is with the Van Gogh Museum in Amsterdam which I point out whenever I receive questions regarding this artist. Despite of a good relationship with my colleagues in Amsterdam there are cases where our opinion differs.

In conclusion, I would like to say that any catalogue raisonné – as any study on an artist – constitutes a contribution toward art history, increasing and improving but not completing our current state of knowledge.