Gammarelli is a tiny family-run shop by the Pantheon that has a nice tradition: it is the only place where the Pope orders his clothes. And this goes back at least over two centuries. If you enter the store (which I highly recommend you do since you are in front of it!), check out the pictures hanging on the walls: papal photos dating back to the reign of Pius XI in the 1920's and framed certificates proclaiming Gammarelli the official pontifical haberdasher.
While I was in the store, the sales people mentioned to me that during papal elections, Gammarelli delivers three sets of robes to the Apostolic Palace: tall and large, tall and slender, short and heavy. This is being done in order to make sure that the new pope has an outfit to wear while greeting the crowds in St. Peter's Square right after his election. Tailor-made robes are stitched later.

