The image of 17th century artist Rembrandt laughing might stun casual art observers who are only vaguely familiar with his art.

The general public is surely more acquainted with other paintings by the Dutch artist, such as the Man in a Gold Hat, The Return of the Prodigal Son, The Night Watch, The Anatomy Lesson, or The Descent from the Cross. That could explain why a recently discovered portrait by Rembrandt on display at the Toledo Museum of Art might not seem to be in accordance with the renowned artist's other works.

But it's also exactly why Rembrandt Laughing, discovered only a few years ago, is so absolutely Rembrandt. His art is unpredictable, with paintings that depict history, family members, landscapes, and animals -- and of course, portraits of himself and others.

To label Rembrandt Laughing as a self portrait is not quite how the head of the Rembrandt Research Project in Amsterdam describes the little painting.

"I have problems as to how to refer to the portrait. Is it a self portrait?" Professor Ernst van de Wetering said during a telephone interview from his home Amsterdam.

The world expert on the artist will lecture at the museum's Peristyle at 7 p.m. Thursday. The portrait has been on loan from a private collection, courtesy of Hazlitt, Gooden & Fox of London, to museums in Fort Worth and in Denver. It is on display in Gallery 24 at the Toledo Museum of Art through May 1.

"He got interested in depicting affects, and the best way to do that was to look into the mirror," he said about the work that's only about 6 inches by 8 inches and that shows Rembrandt in his home of Leiden when he was about 21 or 22 years old. "He made a number of etchings of different facial expressions, all very early."

The portrait was believed to have been in the possession of an English family for about 100 years until October, 2007, when members decided to sell it. A London auction house, Moore, Allen, & Innocent in Norcote, Gloucestershire, set its pre-sale estimate at from $1,600 to $2,400 and believed it to be the work of an older Rembrandt contemporary, Frans Hals.

However, art dealers recognized its value and bidding skyrocketed. It sold for $4.5 million, which some believe is far less than it is worth.

Mr. Van de Wetering was contacted to help authenticate the portrait.

The expert considered Rembrandt's monogram in the upper left-hand corner, where it is signed RHL, for Rembrandt Harmensz Leiden, which he used for only a few years. The first letter is for the artist's first name. Lawrence W. Nichols, curator of European and American painting and sculpture before 1900 at the Toledo Museum of Art, said the H is for Rembrandt's father's first name, Harmen. (He explained that Harmensz is an abbreviation for Harmenzoon, which means "son of Harmen" in Dutch). The L is for Rembrandt's native city of Leiden.

Rembrandt Laughing reveals how closely the artist studied every element of his own features, Mr. Van de Wetering said. His hair was a little fluffy at the temples, and he captured his exact type of eyebrow. His eyes convey amusement or lighthearted laughter and his mouth is slightly agape with smile lines on either side.

"In this little painting, which as an absolute masterpiece, he faithfully rendered his own features," Mr. Van de Wetering said.

It's impossible to say that Rembrandt Laughing is different from any of the artist's other work because, Mr. Van de Wetering said, every painting was special for Rembrandt.

"He has no routine. He is an artist in a sense that is close to what we now think an artist should be. In those days, they produced flower pieces or still life. Rembrandt didn't have a speciality," the expert said.

To Rembrandt, everything in the world had to be painted.

"You find landscapes, costumes, historical faithfulness of the rendering of things. He didn't have habits in that sense," he said.

Mr. Van de Wetering has been involved in the discovery of several Rembrandt works of art, each of which sheds more insight on the artist, who spent his life searching.

"Each work you discover throws light on that process of searching. You could never have predicted that such a painting would have existed. So then every work which he made is significant because it always throws a different light on his genius," he said.

This discovery also was a wonderful surprise because, as Mr. Van de Wetering said it's put in the American museum world, "It has very great wall power; strong presence on the wall."

Contact Rose Russell at rrussell@theblade.com or 419-724-6178.

First Published March 2, 2011, 4:23 a.m.