How do you authenticate an artwork?

The little realized truth is that the only person who can authenticate an artwork is the person who created it. If that person is not available (dead or in an asylum) then the best you can do is to find the best authority on the work of the artist and ask for his best opinion.

When the artwork in question is attributed to Salvador Dalí, the best and most credible authority is Bernard Ewell, ASA. His experience and credentials are listed in Salvador Dali - Our Special Focus - “What makes you the expert?” on this website. He prepares formal Professional Opinions of Authenticity following a personal examination of the artwork in question; extensive research into the artist’s career, work and market; comparison of the image with a great many others he has examined; and stylistic analysis. His Professional Opinions always explain the factors that have brought him to his conclusion. Throughout the process he employs the scientific method and has gained fame as an “Art Detective” or “Art Sleuth”.