"Painters are a funny lot," Frederic remarks. "The other great Raphael was dead when he was 38," he says half-seriously. "An awful lot of them die very young."

The new biography and retrospective fill him with "pride and grief". He adds: "It is what the work deserves and is part of our inadequate response to her not being here.

"People should relish the work. There is something more than a visual experience with Sarah's work, there is a sort of imprint. A true artist's work is stained with something. Every piece is stained with something which decorators and commissioned persons of all kinds can never manage. All of Sarah's work carries that strange sense of admiration and menace of the world, which, God knows, I think is a pretty accurate vision of it."