Staff at the Prado, Spain's top art museum and one of the world's greatest art galleries, usually prevent visitors from touching its priceless treasures.
But on a recent morning, with their blessing, Mr Jose Pedro Gonzalez, 56, slowly ran his fingers over a copy of one of 15th century master Diego de Velazquez's most famous paintings, Apollo In The Forge Of Vulcan.
His hands ran back and forth over the depiction of the god Apollo wearing a laurel crown, tracing the edges of the garment.
"There are many things that you can discover and that you love discovering," said Mr Gonzalez, who has been blind since the age of 14.
The painting is one of six copies of works by masters, such as El Greco and Francisco Goya, specially created for the museum's first-ever exhibition for the blind.
They use a relief painting technique that adds volume and texture to allow the blind a chance to create a mental image of a painting by feeling it. "This is a brilliant exhibition. The only way the blind have had to access paintings is through explanations from another person," said Mr Gonzalez, who has visited the show several times since it opened in January.