Everywhere I go lately I see fellas wearing shirts over a shirt. In many cases the shirt on top (worn as a light weight jacket) is just as light if not lightwer in fabric! That makes no sense really. The over shirt should be a bit heavier. Maybe a chamois from LL Bean or a wool shirt from Woolrich (I saw Brooks Brothers at Pitti and thyre doing a plaid one for black fleece). Got to note how this guy wore braces. I like the sort of untucked tucked. It's alot better than the half tuck you see everywhere. Classic. Not for everyone to try. The shirt on top has to fit as a regular shirt would> These days so many guys cant even button the top button of the shirt thyre wearing in general!