The artist, who was attached to the Australian Defence Force in Afghanistan from October 11 to November 3, 2011, as part of the Australian War Memorial's Official War Art Scheme, asked his subjects - serving or retired servicemen and women - to pose nude. All but one of them did.

Curator Lauren Webster said Quilty was exploring the impact of serving in Afghanistan on those involved.

''He was looking at the vulnerability of the flesh,'' she said.

Quilty, 39, said ''wild experiences really drive the work in some ways''.

He was given three days to accept the honour of being an official war artist and was deployed within weeks. He was given the freedom to operate as he saw fit. And that included how he depicted his subjects - including those that he painted nude.

Quilty said: ''When I was in Afghanistan, the uniform and camouflage were designed in some ways to create a threatening presence, to intimidate and emotionally overpower the enemy.''

He wanted to remove all this and have the subjects fit into the more traditional artistic pose of a life model. By stripping away the military trappings, he hoped to get closer to the truth of the events and the experience.

''Skin - we're fairly desensitised to it in Australia,'' he said. ''But a soldier hit by shrapnel or a bullet, their skin is damaged, their flesh is damaged.''

The commissioned paintings from the memorial are Kandahar (2011), Captain S, After Afghanistan (2012), Lance Corporal M, After Afghanistan (2012), Captain Kate Porter, After Afghanistan (2012) and Air Commodore John Oddie, After Afghanistan No. 1 (2012).

Retired Air Commodore John Oddie was the one subject who did not pose nude. Quilty said that when he asked, ''he told me to piss off''. Air Commodore Oddie said he ''might have'' but he wasn't sure if the artist was serious.

In any case, it didn't damage the relationship. Quilty painted Air Commodore Oddie three times.

Air Commodore Oddie was, Quilty said, ''very emotional'' about the challenges of command and, in the end, having him clothed was somehow appropriate. ''He seemed a very paternal figure among the troops,'' Quilty said.

Air Commodore Oddie, 55, was deputy commander of the joint task force and was just finishing his posting when he met Quilty.

He said he was ''somewhat uncertain'' about being painted. But, in the end, he agreed. ''It was a portrait about us,'' he said. ''I saw my role in the portrait as more representative.''

Air Commodore Oddie thought the paintings would help give confidence to service personnel and their families that their experiences were being represented, now and in future.

He said: ''Ben's technique is a very strong technique … it's confronting to some extent by its nature. It's probably not a painting you'd hang in the bedroom.''

But despite the raw nature of the work, Air Commodore Oddie was glad to have sat for the paintings. He said the three portraits Quilty painted of him documented the ''convoluted'' changes he underwent: the process of retiring from active service (he is still in the reserves), starting a new business and establishing a new life.

The five commissioned works were among 20 paintings and 16 works on paper Quilty created from his time in Afghanistan, all to be sent to Sydney.

The memorial's director, Brendan Nelson, who visited Afghanistan several times while defence minister in the Howard government and as ambassador to NATO, said the subjects ''revealed themselves in every sense of the word''.

Dr Nelson said when he first saw images of the paintings, he thought ''this is unusual''. But when he saw them up close, he found them ''immensely powerful''.

After the Sydney season ends on April 13, Ben Quilty: After Afghanistan will tour around Australia. But Dr Nelson said he wanted to have an exhibition at the war memorial devoted to Afghanistan before the end of the year, which would include at least one of the Quilty works. He said this would help the public understand Australia's involvement in Afghanistan and ensure the efforts and sacrifices of those involved and their families were acknowledged and appreciated.

■ Ben Quilty: After Afghanistan opens at the National Art School Gallery, Darlinghurst, on February 21.