Christopher Rothko

In conversation with Observer, the artist's son discusses the genesis of "Rothko in Florence," a 15-year labor of love that places 73 works in dialogue with Fra Angelico, Michelangelo's library and three of the city's most storied spaces.

In his new book, Avrich cites experts who suggest that half, or possibly even more than half, of the artworks on the market today are forgeries.