Caravaggio’s 1609 masterpiece “Adoration of the Sheperds” is getting touched up in public — here’s how to book the free visits.

Like a lot of things worth doing in Italy, it won’t be particularly easy. Groups of 10/15 people will be allowed to watch restorers at work in Rome’s lower chamber of parliament until it is returns to pristine condition in January 2010. Visits are free, but available only Wednesday and Friday afternoons and last about 20 minutes.

Sponsored by broadband telecommunications company Fastweb, the online reservation form shows which dates are still available. (Here’s the Google translation into English, if you need it).

Ever since a restorer acquaintance let me climb up on Giambologna’s Ferdinando I de Medici statue to check out her work, I’ve tried to get a gander at restorations whenever possible, like Donatello’s David at the Bargello or at the frescoes at Santa Croce.

If you’re in Rome, it’ll be worth the trouble.