If you have a work of art that is signed with the name Constant and you would like confirmation of its authenticity you can submit the work for research by Fondation Constant.



Oral assesment

After receiving the application form, photo’s and documentation, a telephone call or meeting for the oral assessment will be scheduled. An oral assessment is free of charge. NB: this assessment does not include extensive research nor any written statements and/or oral statements to third parties!

Written statement
After receiving the application Fondation Constant sends an invoice. When the payment is received, an appointment is scheduled to inspect the object first hand (if possible). In the meantime research is conducted on the documentation and the provenance. When the research is concluded and three experts have separately reached their conclusions a written statement will be issued. If the work is deemed an original by Constant a certificate of documentation is provided and the object will be added to the catalogue raisonné.

€100,- Written statement about authentication
Prices exclude 21% VAT

If you have any questions you can address them to

NB: When we’re busy it can take up to 3 to 4 weeks to handle an authentication.

Fondation Constant is a not for profit organisation and your donations are always welcome and ever necessary:

Fondation Constant