LOS ANGELES (AP) — Before he died 340 years ago, Rembrandt van Rijn lost his house, studio and most of his money. He even sold his wife's grave to pay bills.

Since then, he also has been stripped of credit given to him for hundreds of drawings and paintings.

Experts say many works, once believed to be Rembrandt's, were done by students who would sit at his side, use the same model and come up with similar drawings or paintings.

At one time, Rembrandt was credited with 611 paintings. In the 1930s, scholars said only about half were his. Now comes a study of about a thousand ink drawings once thought to be the Dutch master's.

Between a third and a half of them were done by his students, said Lee Hendrix, senior curator of the J. Paul Getty Museum's Department of Drawings.

An exhibition based on 30 years of research and called "Drawings by Rembrandt and His Pupils: Telling the Difference" will be on display at Los Angeles' Getty Museum opened Tuesday and will be on exhibit until February 28.

There will be more than 40 pairings, showing Rembrandt's drawings next to those by pupils such as Govert Flinck, Ferdinand Bol, Gerbrand van den Eeckhout, Carel Fabritius and Nicolaes Maes.

The display will be in several rooms and will feature original student-teacher drawings paired side by side. Labels will point out the differences in technique, texture, light and angle, while enlarged photos will focus on the differences.

Few of the drawings are owned by the same museum. So about four years ago, Hendrix and Peter Schatborn, emeritus head of the Rijksprentenkabinet of the Rijksmuseum, Amsterdam, started asking for loans around the world.

They asked 33 museums for about 100 drawings. Every one said yes, Hendrix said, calling that unprecedented.

Six drawings from the Getty collection will be part of the show.

"Some exhibitions, you close up the catalogue and put in on the shelf. This is taking the work of many scholars over 30 years, putting it all together in one accessible place, clearly presenting it and changing the perspective on a vast body of art," Hendrix said.

Authenticating a drawing is not as easy as turning it over to forensic investigators. There is no DNA, no fingerprint work, cotton swab tests or test tube chemical that will produce the truth.

"For paintings, there are many scientific instruments that help. For drawings, there aren't," Hendrix said. Ink is just fireplace soot, an organic substance.

So the scholars had to use visual characteristics to identify a core group they knew belonged to Rembrandt or Flinck or van den Eeckhout and work from there. Tedious stuff, and the job is far from finished, Hendrix said.

They started with a six-volume catalogue of over 1,000 drawings attributed to Rembrandt and put together by Otto Benesch in the mid-1950s.

If a drawing is determined to be that of one of Rembrandt's students, it can take a financial toll on the collector, private or public.

"It has affected the market," Hendrix said. "It's always a problematic thing to say to a private collector your work is not a Rembrandt.

"Before you go to auction or go to a private dealer to buy a Rembrandt drawing, you should talk to a lot of people and be really careful. Not every one of (the drawings) has been published."

The Getty exhibit includes lectures, a symposium, classes, discussions, demonstrations, a workshop, a documentary, a concert, audio clips, four books and coordinating exhibits of Rembrandt paintings at five other Southern California museums.

Rembrandt, who lived from 1606 to 1669, was a genius who realised great wealth from his work, Hendrix said, but he lost it all because he spent too much and saved too little.

He taught nearly 50 students in his studio during 40 years, but was evicted in 1658. The building would eventually be turned into a shrine to him.

Rembrandt is Hendrix's "favourite artist ever." She speaks the language, has spent time in his studio and was one of the scholars involved in weeding out the study.

"With Rembrandt, you never come to the end of it. There is always some aspect that is mysterious. Just his perception of light; he was so sensitive in recording it.

"He sees humanity. For example, he was in his 20s when he started drawing old people. Can you imagine a macho, young male artist today spending his time drawing old people?" Hendrix asked.

One of the four books prepared for the exhibit, a 300-page catalogue also called "Drawings by Rembrandt and His Pupils: Telling the Difference," pairs the drawings as they will be displayed in the show. Every drawing in the book except one is the original size.

No one knows exactly how many drawings by Rembrandt or his pupils survived the last four centuries because they are so small and portable (easily stuck between the pages of a book), artists seldom signed them, they were seldom sold, they weren't made into paintings and many were auctioned off in lots after Rembrandt was evicted.

"Very few of them had value as works of art," Hendrix noted. "They were tools in the creative process. Rembrandt kept lots and lots of drawings, both his own and his pupils. He kept them in albums."

When he went bankrupt, the albums were sold and the drawings were mixed and muddled.

Hendrix figures some have yet to surface.

Also, because of the large number of drawings that do exist, she figures the attrition rate was probably very high.

Today, a Rembrandt drawing costs millions.

The works of his students do not carry such price tags, but they are valuable, Hendrix said. The most successful pupil was Eeckhout.

The exhibit will be shown only at the Getty.

www.getty.edu