Wikipedia
Gammarelli
Gammarelli is the official tailor of the pope. The shop is located in Rome. Gammarelli makes for example the zuchetto. It also makes the galero, the wide-brimmed, tasseled hat that used to be worn by cardinals (some do still wear it) and other high-ranking prelates; the cardinals order them or have them given as gifts since Vatican II, and when they die, at a " Month's Mind Mass" a month after their death, the galero is raised to the roof of their cathedral, there to stay until it deteriorates. In addition to Popes and Cardinals, it serves many Archbishops, Bishops, Monsignors, and other prelates and priests.
The company has tailored for the popes since 1797.