New Delhi, Oct. 18 -- The first time he met a pope, Mexican craftsman Hilario Hernandez could not believe his luck. He did not travel to the Vatican as a guest, but as the guardian of the fragile ceramic piece he had created as a gift for Benedict XVI.

"No one really planned to take me along," Hernandez said. "But a Tree of Life can easily break, so I got the chance to bring it myself."

The work he was commissioned to create for the pope in 2008 is a celebrated expression of Mexican craftsmanship.

Known as a Tree of Life, it belongs to a tradition that flourished in the hands of artisans in the mid-20th century and is considered a symbol of identity in Hernandez's hometown.

In Metepec, where he lives and runs a family workshop about 4...