08/02/2012 16:32 GMT | Updated 22/05/2015 10:12 BST

Review: Lucian Freud: Portraits - The National Portrait Gallery

Lucian Freud: Portraits - The National Portrait Gallery Self Portrait, Reflection, 2002 - Lucian Freud. Photo: PA

Perhaps because of the size of some of Lucian Frued's canvases, which border on monumental, you find yourself focusing in on smaller details at the National Portrait Gallery's exhibition of the artist's friends and family paintings.

Man in a Chair offers up a pair of Baron Thyssen-Bornemisza hands which reveal tension, anxiety and age. Naked Man With Rat has the rodent's tail sitting against the model's thigh near an equally naked penis. The Brigadier - a clothed portrait of Freud's friend Andrew Parker Bowles - features a swell of stomach under the confines of a crisp white shirt.

Lucian Freud: Portraits - The National Portrait Gallery The Brigadier, 2003-4 (right) - Lucian Freud. Photo: PA

It is this last detail which is revealing of Freud's approach to painting in general. Clothed or unclothed (Freud's sitters were only nude if they were comfortable being so) Freud would paint the body beneath the fabric. It's a skill which contributes to the effect of psychological vulnerability in his subjects - the idea that no matter the protective layers you wore, he could still see your most exposed self.

Planned as a living exhibition in collaboration with Freud himself before his death in 2011, the show takes in portraits from across Freud's artistic timeline, from the early works of the 1940s which saw him earnestly taking in every detail of his first wife, Kitty's face to the thick paintwork bringing his studio assistant David Dawson to life in the painting he left unfinished on the easel at his death.

The progression from fledgling painter to assured artist is revealed room by room and, although not every piece is a masterpiece, Freud's skill in bringing his sitters' "inner life that's ticking away" to the forefront is more and more in evidence.

Particular highlights are the enormous canvases devoted to performance artist Leigh Bowery and Bowery's friend Sue Tilley where Freud's enthusiasm for both sitters is palpable. The paintings of Tilley in particular betray the artist's fascination with the story told by a sitter's flesh as well as his skill in capturing a very English flavour of lighting.

Lucian Freud: Portraits - The National Portrait Gallery Model Sue Tilley poses in front of Benefits Supervisor Sleeping, 1995 - Lucian Freud. Photo: PA

Michael Auping, chief curator of the Modern Art Museum in Fort Wort, Texas where the exhibition will reside from 2 July-28 October, explains that Freud's paintings exhibit a peculiarly British style which appeal across the pond. The United States is "the land of Photoshop," according to Auping. "The land of no wrinkles - American art is characterised by a flatness and distance."

Grant Wood's American Gothic and Edward Hopper's habit of painting subjects as viewed from an outside viewpoint exemplify this vision of a US aesthetic. Interestingly, the very early works in the exhibition exude the same flatness you find in American Gothic. They're almost painfully meticulous and strangely disconnected, with the body parts created one after another rather than as a coherent whole. The results, slightly bug-eyed and cold.

During the mid-50s Freud switches to coarser paintbrushes and begins to favour working while standing, allowing for broader and more natural sweeps of paint which bring depth and life to the bodies he paints. It is from this point onward that Freud begins to revel in the fleshiness and interior life of his subject and brings a shock of unruly bodily reality to the public eye which is so much the antithesis of Auping's description of American art.

Both Freud's own life and those of his various sitters intertwine in paint and stretch across the canvases in a kind of biography of relationships. When Auping once asked Freud "Why nudes?" Freud answered, "It's the most complete portrait." Looking at the work on display in the exhibition, it's hard to disagree.

Lucian Freud: Portraits - The National Portrait Gallery Visitor looking at Portrait of a Hound, 2011 - Lucian Freud. Photo: PA

Lucian Freud: Portraits, 9 February - 27 May, National Portrait Gallery (advanced booking recommended)