LONDON (AP) -- A Polish man who defaced a Mark Rothko painting in London's Tate Modern gallery with black ink to promote an obscure artistic creed was sentenced Thursday to two years in jail.
Wlodzimierz Umaniec, also known as Vladimir Umanets, was arrested after visitors discovered a scrawl across the bottom of Rothko's "Black on Maroon" on Oct 7.
The 26-year-old later said he had written the words "a potential piece of yellowism" on the abstract painting to draw attention to Yellowism, an artistic movement he co-founded. A manifesto on the website thisisyellowism.com expounds upon the terms "art" and defines the concept as "not art or anti-art."
Umaniec pleaded guilty to criminal damage over 5,000 pounds ($8,000). Prosecution lawyer Gregor McKinley said restoring the painting would cost around 200,000 pounds ($320,000) and take up to 20 months.
"Complications to this work include the unique painting technique used by the artist and the fact the ink used by Mr. Umaniec has permeated the paint layers and the canvas itself," he said.
Passing sentence at Inner London Crown Court, judge Roger Chapple said it was "wholly and utterly unacceptable" to promote the movement by damaging a work of art that had been "a gift to the nation."
Tate Modern said in a statement it was "pleased that the court has recognized the severity of this incident and its consequences."
Ben Smith, a self-described yellowist who came to court to support Umaniec, said the attack on the painting had made yellowism "a global phenomenon."
"This was not an act of destruction. It was an act of creativity," he said.
He said Umaniec's time in prison would give him "a greater understanding of humanity."
Russian-born Rothko, who died in 1970, was a leading figure in American abstract painting, renowned for large-scale works featuring bold blocks of color.
The defaced painting was one of a series intended to decorate the Four Seasons restaurant in New York. Rothko changed his mind about the commission and gave the works to galleries, including the Tate.
McKinley said auctioneer Sotheby's had valued "Black on Maroon" at between 5 million pounds and 9 million pounds ($8 million and $14 million).
This is not the first time an artwork at Tate Modern has been interfered with. In 2000, two Chinese performance artists attempted to urinate on Marcel Duchamp's urinal sculpture "Fountain."