Beltracchi was caught because of a fake Heinrich Campendonk painting titled "Red Picture with Horses." The new owners commissioned a scientific analysis. It turned out there were traces of titanium white on the canvas, a pigment that Campendonk couldn't have used because it didn't exist at the time. "I took a zinc white from a tube, a Dutch product, but unfortunately it didnt say that it contained a small amount of titanium white," Beltracchi told SPIEGEL. "In other words, the whole thing was discovered because of an incorrectly labeled tube."