Certificate Request

Please find below the elements to send us for each work in order for us to deliver their certificates of authenticity.

Terms and Conditions

We can only answer to requests coming from the current owners of the works or any mandatary who can prove having received the delegation of this request by the owners. If you are a potential buyer, or the payment for the work has not been made in full, you have to ask the seller to contact us to obtain the certificate so that they can provide it to you.

Do not send requests regarding reproductions on paper (lithography or offset) or autographs.

A fee per each certified work is required to fund the Committee’s activities:

  • € 1200 for a work on canvas or panel
  • € 800 for a work on paper or cardboard

Your sending of the information and documents requested below brings your certificate(s) request into being, and therefore your commitment to bear the resulting costs. The Committee does not commit to providing an answer. When your certificate will be ready to be issued to you, we will ask you to send us your payment by bank transfer (bearing the bank fees on both sides in case of an international transfer).

The certificate must always follow the work in case of resale, and will not be replaced in case of loss.

It is important that you acquaint yourself with all the information below, we will only answer to complete files sent through the provided links. Because asking for missing elements is a very time consuming task, we may discard, without providing an answer, any request that does not provide all of the expected elements, or that provides the elements by another method than the one expected.

Please note. The Committee is not a commercial enterprise, it is a service provided by the artist’s family. There is no guarantee of delay. We do not respond to urgent requests. Each response typically occurs after one month. All emails are read, it is not necessary to follow up with multiple emails. Any unjustified follow-up, or any follow-up copying a third party, will reduce the priority of your request. Moreover, please only contact the Committee by e-mail. If you call a private phone number without prior agreement, your request will be postponed or ignored.


  • Known title and year of work
  • Exact dimensions of the work (height x width, in cm to the nearest mm, both with and without the frame)
  • Description of the medium and technique used
  • Any information or story about its origin, its successive owners, the exhibitions where it was presented, any restoration work
  • The name and the postal address to be used for the invoice and for the delivery of the certificate (it must be the owner of the work or their mandatary in due form)
  • Your cellular phone number, should the Committee need to contact you
  • The indication of ownership that could appear in a catalogue raisonné (e.g. “private collection”)
  • We will ask you to present the work physically, at your expense, in a gallery or auction house of your choice in Paris, or in a storage facility in Paris or its immediate suburbs. We will not be able to hold it in storage. Please provide possible dates and times in the upcoming two months.

How to send the information

To send this information to the Committee, click here or send an e-mail if you have already received a reply from the Committee by this means.


  • High resolution scans of any previous certificate of authenticity (in the case of a certificate issued by Georges Mathieu, you will have to send us, at a later date, the original copy of the certificate by registered mail, which will be returned to you)
  • High resolution scans of any document related to the work (publications or catalogs, ownership certificates)

Digital photographs

Digital photographs must be sharp, unretouched and in the highest resolution possible (min. 12 million pixels). They must be taken with professional or semi-professional equipment (DSLR on tripod, eg. Canon EOS, Nikon D or Sony Alpha) without reflection or perspective effects. Smartphones are prohibited. We can use most RAW files (eg. .cr2, .nef, .arw, .dng, these are the recommended filetypes but they are very large) or else all TIF and JPG files (for JPG be sure to set the quality to maximum).

  • Front of the work, including the frame if present
  • Front of the work next to a ruler and, if possible, next to a photographer color chart (for instance X-Rite ColorChecker)
  • Back of the work, including the stretcher for works on canvas
  • Detailed close-up of the signature, or of each signature in cases where there is more than one
  • Detailed close-up of each writing on the work or medium: labels, stamps, inscriptions, or any other sign even if it is slightly visible, either on the front, back or sides, either on the medium, the stretcher or the frame (pay attention to the possible presence of a title written in pencil on the frame, which may be very faded)
  • Detailed close-up of a few parts of the work, both on the foreground and background of the work, in order to report the state of preservation, the techniques used and the gesture’s dynamics
  • Detailed close-up of any deterioration if present (lack of pictorial material, scratches, marks, tears)

We recommend that you enlist the aid of a confirmed photographer. If you do so, make sure that the photographer explicitly acknowledges that the Comité Georges Mathieu exclusively holds all reproduction rights on Georges Mathieu artworks, and consequently on the photographs he or she produces.

By transmitting photographs to us, you acknowledge that the Comité Georges Mathieu exclusively holds all reproduction rights to them. Therefore the Committee can freely use them, including in the context of a catalogue raisonné, books, exhibitions and online publications.

How to send the documents and digital photographs

You must send the requested files through the following web page: https://georgesmathieu.wetransfer.com

Files sent via other means will be ignored.