Rare glimpses of Frank Auerbach Apparently self-taught as an art historian, she produced a complete catalogue of the etchings of Canaletto in 1974. In the early Eighties, she and Joseph suffered the loss of their only child, Michael, from a brain tumour, aged 28. Art thereafter became something of a refuge. Having worked for the art dealers Colnaghi's, she developed an interest in the modern British painter Walter Richard Sickert, after her husband gave her a Sickert print for her birthday. Discovering there was no reference work on Sickert's prints, she embarked on producing a catalogue of them, which came out 10 years later, in 2000. The sittings began in 1992, and continued every Thursday for the next 17 years, during which time some 20 portraits were finished. Gordon Cooke of the Fine Art Society, which exhibited her Sickert collection, remembers how Ruth was "always busy on a Thursday," but even he didn't know why for quite some time. "She never talked about Auerbach," he says. But it was a measure of the respect in which she was held that when the gallery exhibited her collection of Sickert prints both Auerbach and Freud were at the opening. A rare occurrence. In an interview with Catherine Lampert, conducted in 2001, Ruth described how her portrait sessions would be structured: 45 minutes in which "Frank begins to paint over the remains of the scraped-down version of my previous portrait sitting," accompanied by discussions on art and artists, but then followed by an hour of painting in complete silence. When Ruth wrote to him to thank him for giving her a painting he replied that "the greatest present is your consistency as a sitter, and your patience with my slow fumble towards the truth." This consistency only came to an end in March 2008, when ill health forced her to resign as a sitter. "I know how important your sitters are to you, and I would not wish to be the cause of disruption to your work schedule," she wrote apologetically. Thursday afternoons will never be the same again, and I feel the loss. I cherish my hours spent in the studio - my home from home. She finishes by pointing out that both Auerbach's first and last painting were with her at home as a source of constant pleasure. Two years later, she was gone. It is tempting to see in these portraits a relationship between a bereaved mother and an orphaned son. Whether that relationship existed is not known; sitting for Auerbach may have been an intensely personal experience, but also a very private one. What we are left with are not portraits in the conventional sense, but powerful and intense evocations of the essence of the sitter rendered with the unmistakable flow of the painter's brushes. Estimates have been set between £150,000 and £650,000 for each painting, or in excess of £1.8 million for the whole series. The proceeds will benefit the Art Museum of Israel in Jerusalem in memory of the Brombergs" son, Michael.