While exhibition catalogues of his work abound, there are only two books on Frank Auerbach: the first, by Robert Hughes, was published in 1990; the second, by William Feaver, came out in 2009. Thus, as the artist enters his eighty-fifth year, a new book about him and his painting is particularly welcome. Its author, Catherine Lampert, could hardly be better qualified for the task: she is both a close confidante of the artist, having patiently sat for him for decades, and the curator of several large-scale exhibitions of his painting, including a forthcoming retrospective that will be shown at Tate Britain from October 2015 until March 2016.

As the book’s subtitle, ‘Speaking and Painting’, suggests, this latest attempt to shed light on Auerbach’s highly private and oddly exotic world consists essentially of a collage of the author’s observations and the artist’s own statements and remarks, taken from the numerous interviews he has given over the course of his long painting career. Having interviewed him on several occasions myself, I know how fluently and memorably Auerbach talks about every aspect of his work, from the subjects he attempts to pin down day by day – first in drawings, then in paint – to the whole complex process by which a new image that the artist deems acceptable comes forth as the unforeseen offspring of repeated trial and error. As anyone at all familiar with the artist will recall, this painstaking technique involves the daily scraping off of a rejected, thickly layered picture to make way for further attempts to trap the eventual image spontaneously within the coils of paint. The verve and ingenuity Auerbach displays in discussing his working methods closely resemble the flair and commitment he brings to the act of painting itself. Just as he obliterates one image after another, so he prunes and rephrases many of his statements before they are published.

But if he can be drawn very happily into detailed examinations of his work, Auerbach is noticeably reticent when it comes to any questions about his life beyond the studio. Lampert admits at the outset, ‘in writing about Auerbach, a biographical approach is not really appropriate’. She refers to his standard catalogue biography in which one terse phrase, ‘1939: Arrived in England’, assumes all the implications of his being suddenly transplanted as an eight-year-old Jewish German boy from Berlin to England and later learning that both his parents died in Auschwitz.

Having followed Auerbach’s work closely over the last half-century, I have to admit that my main interest in reading this book was to find out more about how that dramatic and inevitably traumatic event shaped the artist’s sensibility. I’ve always assumed that his obsessive, repetitive recording in paint of the things closest to him – his studio, its immediate environment, a handful of lovers and friends – stemmed from a deep need to feel as rooted as possible; and that the manic scraping off of one image after another actually provided a way in which he relived and attempted to exorcise that early uprooting.

Lampert does what she can in the circumstances and gives us as full an account of Auerbach’s early years as we are likely to get. It describes young Frank being whisked away from a coddled existence as the only child of older, overprotective parents to a spartan, agreeably anarchic-sounding school in Kent called Bunce Court. Rather than feeling sorry for himself, however, Frank appears to have taken to the place with gusto, picking up basic English and becoming a scout in short order: a photo in the book shows him as a plump and grinning new boy in the school’s bucolic grounds. But if one might expect the growing child to be progressively overwhelmed by the savagery of his fate, one is sharply disabused by the artist himself. ‘I think I did this thing which psychiatrists frown on: I am in total denial,’ Auerbach is quoted as saying here. ‘It’s worked very well for me. To be quite honest I came to England and went to a marvellous school, and it truly was a happy time. There’s just never been a point in my life when I felt I wish had parents.’

Thereafter, Lampert traces the development of Auerbach’s art and his art-world career very ably, supplying a variety of telling and entertaining details. I was amused to learn, for instance, that to pay his way Auerbach helped out at one of the bakeries owned by Leon Kossoff’s family, with Frank on the bread counter and Leon selling the cakes. It is revealing, too, that when he is actually painting, Auerbach frequently shouts out loud, cursing his own desperate efforts, or starts reciting poems from memory. It is also reassuring to know that he himself experiences a certain confusion when looking back at his own paintings: peering into a Mornington Crescent scene, for instance, he once reflected, ‘I can’t remember if that is a man or a cement mixer.’

There are also many less anecdotal aperçus in this handy compendium. I was struck by an observation made long ago by that perceptive art critic Andrew Forge: ‘The closer the circle tightens round [Auerbach] and his model, the smaller the field within which spontaneity is possible – and the more desperately necessary spontaneity becomes … his pictures include the eye’s swoop across a yawning excavation or into the hollow of an eye … He wants the movements into his pictures to be swift and deep and ample, as they are in Rembrandt.’

However apt or revealing this patchwork of commentaries and incidental detail becomes, it can clearly be no more than a series of ‘raids on the inarticulate’. ‘Painting is a dumb activity,’ Auerbach wrote in a letter to me in 1963. ‘The words exist around the periphery of painting, contradictory, rhetorical, fragmentary, generalised – one hopes that they may leave loose ends which lead back to the central activity. It simply does not matter what painters say.’

Not much has changed since then, least of all Auerbach’s unswerving devotion to his endlessly surprising and illuminating ‘dumb activity’. Reading this book subtly raises one’s awareness of his imagery, sharpening one’s excitement at the prospect of seeing the whole trajectory of his art – raised as if on a stage for renewed exploration – in the Tate’s forthcoming retrospective.