Ralph Wolfe Cowan has spent a lifetime painting romantic portraits of kings, movie stars and moguls, even the occasional mobster or dictator, but all anybody wants to talk about is a picture he made of a guy that hangs in a bar.

Not just any bar, of course, but the dark, wood-paneled one at Palm Beach’s opulent Mar-A-Lago club. And not just any guy.

The 1989 portrait is called “The Visionary.” It features a young, tanned and handsome Donald Trump dressed in a white tennis sweater, “his skin glowing like the top floors of Trump Tower at sunset,” as Playboy magazine once described the painting.

It’s such a startling, alternative image of Mar-A-Lago’s proprietor and the Republican candidate for President that reporters who have thronged to the gilded mansion during this election season can’t keep from commenting on it.

The picture has shown up on newspaper and magazine websites from London to New York, and has led to a late-life burst of publicity for Cowan, the 85-year-old West Palm Beach artist and friend of Trump.

A genial Southern storyteller, Cowan is happy to spend hours talking about his globe-trotting encounters with everybody from Middle East potentates to Elvis Presley, Marilyn Monroe, Princess Grace and Michael Jackson.

But for the past year, reporters have quizzed him mostly about Trump, especially the years-long saga of how Cowan came to paint — and then, at Trump’s insistence, repaint — the hand on the Mar-A-Lago portrait.

And who can resist a story about Donald Trump and his hands?

It started when Cowan pulled his convertible into the open gates of Mar-A-Lago soon after Trump took over at Marjorie Merriweather Post’s estate in the 1980s. “You’re new here, I want to paint your portrait,” Cowan told Trump.

They agreed on an oil study, and Cowan spent several weekends when Trump was in town preparing sketches.

As an artist, Cowan wanted to capture a sunnier side of Trump. “I wouldn’t paint you in a blue suit and red tie,” he told Trump. “That’s your New York look.”

Cowan also wanted to do it in a classic mode, where part of the portrait is left underpainted on purpose. So, in the picture, he decided to leave the left hand resting on Trump’s thigh in that style. The hand was visible, and perfectly formed — let’s not go down that road again — but it was a bit on the pale side.

“I love the sketch portraits, where one hand is finished and the other isn’t,” Cowan explained on a recent afternoon in his cluttered studio in the Northwood neighborhood.

Trump accepted the painting and hung it proudly at Mar-A-Lago. “He loved it,” Cowan said, but it soon became clear that “he didn’t get” the hand thing.

And for more than a decade, as Cowan and Trump met at Mar-A-Lago (Cowan holds his birthday party there annually), Trump kept bringing it up.

“He’d say, ‘When are you going to finish my painting?’” Cowan recalled. “I’d say, ‘Donald, it is finished.’ One day, he said to me, ‘How much would you charge to fix the hand?’”

Some reports claim Cowan charged $4,000 to repaint the hand. Cowan said “a couple thousand.” Other stories have quoted Cowan that the painting’s original price tag was $24,000. Cowan said it was less than $18,000.

Cowan doesn’t work for free. On commission, he once did a sepia portrait of the kids — Ivanka (“so marvelous”), Eric, Donald Jr. and Tiffany (“They all have great manners”) — as a surprise from second wife Marla to Trump. But he hasn’t painted current wife Melania and son Barron because he says Trump, around the time of “The Apprentice” show, started expecting things at no cost. “I felt bad, but I said, ‘Donald, I don’t give away paintings.’”

The hand kerfuffle remains perplexing to him. There are stories of people taking tours of Mar-A-Lago and hearing that the portrait was free and another artist repainted the hand. All not true, insisted Cowan. “People think I held out (for more money) by not finishing it,” said Cowan.

Still, he won’t engage in “anything unkind” about Trump. He credits Trump for steering painting commissions his way by bragging to Mar-A-Lago patrons that Cowan is “the No. 1 portrait painter in the world.”

“People love a painting with a story,” Cowan said. “The bigger the story gets, the more famous the painting becomes.”

And if there is anybody who knows about paintings, big stories and the famous people behind them, it’s Ralph Wolfe Cowan.

Dressed in a white blazer, crisp black shirt and jeans, Cowan — R.W. to his friends — is sitting in his sprawling Northwood compound, thumbing through a book of his paintings. The living room — a true artist’s lair — is crowded with vintage chairs, classical statuary, framed portraits and photos of pals Johnny Mathis, Imelda Marcos and Prince Albert of Monaco. Meditation music plays softly as Killer, Cowan’s perfectly groomed Shih Tzu, patrols the tiled floor.

On the wall, there is a large, naturalistic painting of a muscular, naked man sitting cross-legged on a red blanket. That’s Cowan himself — a self-portrait from the 1950s.

The distance between then and now is on Cowan’s mind these days. He had a stroke in 2013, and while he’s recovered and is painting as vibrantly as ever, it’s another reminder of creeping mortality.

“I hate old age,” he said. “I hate everything about it. I’ve become a recluse. I’ve got Netflix and I revisit old friends.”

Those old friends are the musicals he watched as a child growing up in Portsmouth, Virginia. While pals attended dime-theater westerns, he would pay a quarter to see Betty Grable and Alice Faye in Technicolor, dazzled by the tan shadow lines traced above Grable’s eyes.

“Ever since I paid that quarter to see Betty Grable, I’ve always wanted to paint beautiful, wonderful, exciting people.”

From an early age, when he created likenesses on his mother’s ironing board cover, he knew he’d be a portrait painter. After high school, he attended the Art Students League in Manhattan, did a stint as a stateside Army paratrooper, worked briefly as a New York model and had a briefer marriage that produced two sons, now in their 50s.

Mostly, he chased a career across continents, with studios in New York, California, Las Vegas, Miami, Palm Beach and eventually West Palm Beach, where he has lived and worked since the mid-’80s.

It’s been a glamorous life — dancing at the Coconut Grove and the Fontainbleau, doing album covers for Johnny Mathis, stamping an international passport from the Philippines to Monaco to prepare photographs and sketches that he translated into Old Master-style, full-length portraits of sultans, princesses and maharajahs.

“You live very high — a couple days a month,” Cowan said of his have-tux, will-travel lifestyle.

The rest is work.

Royalty, for example, doesn’t mail a check. You have to woo and flatter them, make appointments, hold audiences and spend weeks pinning them down to signed contracts. “The rich are very lazy,” he observed.

Inevitably, his artistic desires would clash with a subject’s self-regard. “I paint somebody and give them the Ralph Cowan magic,” he explained. “I take off 10 pounds and make them look really healthy. I give them a strong neck.”

And still it’s not enough: “They want 20 years off.” Or a repainted hand.

Experience also taught Cowan to never stay at a subject’s house, said Steve Mohler, Cowan’s longtime agent and manager. “Ralph would say you have no idea who was going to be knocking on the bedroom door at 1 in the morning — the husband or the wife.”

There is no shortage of Cowan anecdotes:

Visiting Mar-A-Lago, pre-Trump, in the ’50s and sitting next to heiress Merriweather Post at a 50-foot-long table of solid marble. Painting Vegas mob guys who paid thousands in cash for portraits of their wives — and mistresses. The time Cowan ate collard greens with a 16-year-old boy and then realized it was glamorous Diana Ross, without makeup. Or dancing with Elizabeth Taylor: She had eyes as advertised, but her arms were shockingly hirsute.

Zsa Zsa Gabor once visited the Northwood studio. She admired a Cowan portrait of a rooster. She started to carry the painting to her car. “Not until we get the check,” Cowan told her firmly.

He first met Princess Grace and Prince Rainier in the ’50s, when he hustled a portrait sketch of the former Grace Kelly to a go-between. Amazingly, the couple stopped by his New York walkup, and ate breakfast with him.

Rainier “saw the painting and said, ‘R.W., I’m very, very jealous of you. You saw a look of love in her eyes that I thought only I saw.’” Cowan’s portrait graced Monaco’s royal Christmas card, and he visited the family to make paintings that still hang in the Monte Carlo palace.

When Cowan had a studio in another palace — Caesar’s in Vegas, late ’60s — he kept getting calls from an Elvis impersonator. Or so he thought. But it was really the King, who liked Cowan’s portrait of Johnny Mathis dressed in white (“It’s the star color,” Cowan said).

Presley wanted one done the same way, but had an unexpected request.“R.W., I want the full-length portrait of me nude,” Cowan quoted Presley as saying on one late-night call, when Cowan admittedly had a few drinks.

“I love the idea,” Cowan replied. “But Elvis, if I paint you large-scale in the nude, you couldn’t keep the pose up that long.”

They’d both laugh and keep talking. Cowan eventually painted the portrait, the only one ever commissioned by Presley, and it hangs at Graceland to this day.

According to Presley’s ex-wife, the picture even had medicinal power. “Priscilla called me one day … to let me know how upset she was that one of the more crazy fans had put her hand on the crotch of my Elvis painting and swore it healed her arthritis,” Cowan related in his portrait book, “The Painted Face.”

Cowan, who also has an Elvis portrait hanging in the Smithsonian, admired Presley’s manners, and thought highly of him even if he was, and is, a Mathis man. “You can’t tell exactly why you like somebody,” Cowan said. “I go by how I’m treated, not how the world thinks of them.

”He didn’t think as highly of Presley’s one-time son-in-law, Michael Jackson. He painted an allegorical picture of Jackson in a knight’s armor, surrounded by dogs, a macaw and a spaceship. Cowan then got a call from the King of Pop wanting a change: “Mr. Cowan, I don’t like dogs, I like monkeys.” He made the switch.

Cowan eventually visited Jackson’s Neverland estate in California, and they climbed into Jackson’s tree house together. But he saw things that disturbed him. And Cowan, by now sober, knew the warning signs.

“You can tell when a person is killing himself,” he said. “What I didn’t like was what he was doing to himself.”

As the years go by, he can recall a vague outline but not all the detail work. He met Marilyn Monroe a few times. Once, when he ran into her on the street in New York and she was being wolf-whistled at, she came into his hotel apartment to escape. Naturally, he sketched her a little.

Who knew he’d be asked to remember their conversation 50 years later? “We’d just talk about dumb stuff,” he said. “It was ordinary things, like how you wear your hair. You never knew it was going to be famous.”

Speaking of, Cowan’s 1930s Northwood abode, spread over six lots with a house, dining room, studio, red velvet bedroom and a pool ringed with Greek statues, was once featured on Robin Leach’s old show, “Lifestyles of the Rich and Famous.”

“I’m not that rich and I’m not that famous,” Cowan quipped. “We borrowed a friend’s Rolls-Royce and parked it out front.”

Cowan’s vast web of connections once led him to judge beauty pageants — Miss Hawaiian Tropic, Miss Universe. What’s the secret of judging?

“You’ve got to be cold as ice,” he said. “Don’t go to the afterparty. Some of the women want to know why you didn’t pick them. I learned to go right back to my hotel room.”

His appearance on the old TV show “To Tell The Truth” is another classic Cowan anecdote.

It began when a mugger yanked a $1,000 gold chain off his neck after Cowan got a chicken sandwich at a West Palm Beach Burger King in 1989. Police asked him if he could identify the suspect. He could do better. He went home, painted the suspect (“I have a photographic memory”), put the canvas in a gold frame and delivered it to police headquarters. “In my 10 years with this department, I have never seen anybody go to this extreme,” Detective Jack Yates said at the time.

They never caught the robber, but the tale went national and he was invited on the game show.

He’s still got the picture somewhere around his studio.

When he had a stroke three years ago, it was unclear if he’d ever return to painting.

He couldn’t walk for two months, and was partly paralyzed on his right side. His manager Mohler was scared. But slowly, Cowan began to regain strength.

He pointed to an easel. “When I get in that 5-square-foot spot with the lights and the paints, I feel comfortable,” he said. “The excitement of painting was so strong that I didn’t feel the weakness of the stroke.”

Cowan isn’t jetting around like old times, but he’s keeping busy. A former apprentice is working to raise money to complete a film documentary of Cowan’s life called “The Last Old Master.”

He just restored his Mathis painting that was partially destroyed in a fire at the singer’s home. He’s doing a new portrait of Prince Albert of Monaco. He wants to paint President Obama before he leaves office.

Cowan says there’s no such thing as retirement for a portrait painter. But he’s got an idea for the finale.

Of course, it’s another story — about Monet, painting outdoors and eating watermelon …”and he falls over dead, in the middle of a brushstroke.

“That would be good,” Cowan said. “But I want to do a few more portraits before I go.”