41 Action News has an exclusive sneak peek at the masterpiece inside the room that few ever get to see.
"It's a very important painting in our collection. It was purchased in 1930," said Scott Heffley, Nelson-Atkins Senior Conservator of Paintings.
The Penitent Magdalene from Spanish Renaissance artist El Greco is one of the first pieces ever collected by the Nelson-Atkins Museum of Art. Scott Heffley is working to restore the famous painting to its original condition.
"Several hundred years ago it was restored badly," Heffley said.
Heffley uses technology created long after the piece was painted in 1585.
"I used the microscope, take x-rays, infrared light, ultraviolet light and really understand what the problems are," Heffley said.
Then he tediously tries to restore the painting, thanks to a donation from Bank of America.
"Anything we can do to make sure these treasures are able to be enjoyed for generations to come is a very worthwhile project," said Jack Ovel of Bank of America.
The donation also let Heffley travel around the world to see how other El Greco paintings were restored.
Heffly expects it to take a year to finish because the sunlight is only good for a few hours a day to be able to match the original paint.
"It requires good natural light," Heffley said, "If it's a cloudy day, I can't paint."
Heffley plans to finish restoring the painting later this year – in time to loan it to Spain for the 500th anniversary of El Greco's death.
"I pull back bits of original that are left and unite those so the painting is a masterpiece, again," Heffley said.