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Сообщение от Tjutchev

As an opponent you can argue that, because of the popularity of creativity Klever YY His work poddelavalis during the life of the artist, and Chemical analysis has never been a defining moment in the examination of works of art.

I agree, but there are other opinions.
For example:

Сообщение от SergeiSK

Klever in Russia know only Ignatova and Rimsky-Korsakov, here Lomize, which has had some punctures with certain authors. In addition to her expertise here have to be technological expertise. Need to check match pigment signatures and pigment paintings. If there is no match for the paint - the authorship is doubtful.