AN ART catalogue lies on David Henty’s kitchen table splayed open on a portrait by the celebrated late Italian painter Amadeo Modigliano.

Mr Henty has been studying the painting – the distinctive elongated face, the black, pupil-less eyes – and working out how the paint is laid on, which colours to use.

Once he has done all that, he will head for his balcony overlooking the Channel, and paint a replica.

He might even add the artist’s inky black signature in the corner.

His final step is to stick it for sale online. Quite possibly before the light fades over his Saltdean view, he will have made several hundreds, if not thousands, of pounds.

“It’s a great life,” says the self-described forger, who has been making a living for at least the past five years selling his knock-offs of works by Monet, Vettriano, L S Lowry and other masters via the internet.

“One day I knocked out three little Lowrys by eleven o’clock.”

This is not the living the 56-year-old would ever have imagined for himself. Raised in Brighton, his first job was dealing antiques and cars with his father. Then he was sent briefly to prison in the Eighties, for forging passports, which is where he started learning to paint.

“I had two art teachers there who were really nice,” he recalled. “If I saw a picture, I would just paint it straight on. They would say, ‘you cannot do it like that, it is not the way to do it’.”

Outside of prison, he carried on. For his mother, he painted a copy of the world-famous Proserpine, by Dante Gabriel Rossetti. He also did his own work, often portraits, but sales never really took off.

“I did not know how to use the internet and there was not really a great market,” said Mr Henty, who often spends his mornings kick-boxing before returning home to his easel, oils and pet dogs.

“I did a few and I sold a few, I had an exhibition down on the Marina, but there was not really any money. But then my sister’s husband asked me to do a Monet. So I knocked him up a Monet, and I got more money for it.

“And you sort of think, a light comes on and you think, ‘someone else wants it’. Then I did a lot of Van Goghs. People were queuing up; I could not paint them fast enough.”

He got more formal training with a local art teacher, and became very good at what he does. He continued trading locally or giving copies to friends. Then eBay, the online trading site, became a major force.

Mr Henty set up an account to sell his paintings, and orders from all over the world starting pouring in. He has shipped paintings to Australia and Japan. Rooms at home are crammed with canvasses to paint or works ready to go out.

His first sale on eBay, he said, was a Lowry. “I sold it for £3,500,” he recalled.

“And I thought, ‘This is great, what a fantastic way of making a living’.

“I was getting fantastic feedback. I was an eBay power seller.”

The painter does not believe he is doing anything wrong.

He says he does not say the paintings are originals, nor do people realistically think they are, even though he often adds the artist’s ‘signature’. eBay disagrees, however, and recently banned him from selling, saying he was breaching their policies.

“I took advice from a solicitor when I started,” Mr Henty says, “and he said, ‘as long as you put you are selling it as ‘after’ or ‘in the style of’ the artist you can sign it, you can do what you like, but it is not criminal’.

“People are not going to buy a Lowry for a few hundred pounds and think it is worth £400,000. It is just mad.

“The problems come if you try to sell it as real. But if you try to sell it as a copy, that is fine.

“I have seen lots of my paintings in meetings [auctions] as real but that is nothing to do with me. What they do [with them] after they get out of my hands is up to them.”

His prolific output includes copies of work by Winston Churchill and Gillian Ayres.

He is currently learning about Edward Sega. He is happy to admit he has “nothing to say” as an artist himself, but enjoys understanding others’ work.

“I like the technical side of it ,” he said, “Seeing the painting, then de-constructing it. That’s why I like forging because I like working out how the artist has done it. You have to really look at it, look at the colours, work the palette out, then look how they put the paint on. Then what happens is you click into it, into that person’s footsteps, basically.

“If I saw a new artist I would go and find his work somewhere, I would have to see his work before I can copy it.

“I also try and read everything about him I can, soak myself in everything I can find out about the artist. It’s like being obsessed for a little while.”

One master has so far escaped his paintbrush: Lucian Freud. “Most I can get efficiently and can paint,” said Mr Henty, thumbing through a catalogue of the artist’s works.

“But Lucian so far has evaded me. I have not quite mastered it yet, his work. When he paints he is really slow and builds up bits and pieces and it probably took him about a year or 18 months.

“One of his paintings went for £16 million. And here, the woman looks like a man and I thought, if I painted that... It’s a funny picture and I thought, ‘I could not get away with it’.”

Mr Henty, who has a copy of ‘Buy the $12 million Stuffed Shark: The Curious Economics of Contemporary Art’, by Don Thompson, on the kitchen table, does not lose sleep over artists missing out because he is capitalising on their work.

“I don’t do many people who are alive, I try and wait until they have gone,” he said.

“Most ordinary people are not going to be able to put a quarter of a million pound painting on their wall. But for a few hundred quid you can own one that looks like it. I am just bringing art to the masses, affordable art.”

If anything, the zany world of art prices bolsters his sense that it is all fair game.

“You can have a really crap painting that you would not want to give to your family, but if they have got ‘that’ name it will go for millions,” he said.

“I went to a couple of Charles Saatchi shows and I came out and thought they were absolutely crap.

“But he is such a powerful character that if he says, ‘I like that,’ then you have got about 20 dealers behind him saying, ‘I will buy that’.”

Despite eBay’s ban, Mr Henty is still very much in business, selling elsewhere online, and with a big grin on his face.

“I just really like my life,” he said. “I get up in the morning, paint. It’s down to practice – some people have got a lot of talent but have not got perseverance.”