My overall response to all your questions is that painting authentication is an inexact science. Given the number of people making a living out of playing the system and doing a good job of making forgeries that include all of the things that experts use to authenticate works of art, it is impossible for anyone to be 100% right 100% of the time. It all comes down to terminology – if the term ‘authentication’ is used, there is an assumption that an objective and scientific rigour has been applied to assessing authorship.

 

Taking a different perspective – let’s think about it in the context of medical science. You have a sore gut and go to your GP. The GP offers an expert opinion about what may be wrong with you and provides suitable remedies and prescriptions. A week later, you’re still unwell, so you return – ie: your GP was wrong. GP sends you to a specialist, who also offers an opinion. Another week later, still sick (ie: your specialist was also wrong in the expert opinion she formed), you head back to the specialist, who recommends a biopsy. In the lab, what’s really bothering you is identified and a course of treatment plotted out. Lesson from this, as in the art world – no expert is ever 100% right 100% of the time. But the art world is particularly tricky as you have unscrupulous people setting things up to also fool the scientists in the lab, as well as fabricating ‘symptoms’ (provenance etc) to deliberately fool experts.

 

The most effective way to authenticate a painting is to combine all three approaches – connoisseurship (expert knowledge of an artist’s ‘hand’), scholarship (examination of the historical record) and scientific examination. If all three boxes are ticked, there’s a better-than-most chance that the work of art is OK. But it’s still not 100%. There are too many variables.