Since I've had several people comment on my "leather against skin" comment, I wanted to tell you what my solution to the problem was. I carry a G19 as my EDC [now I probably carried something else at the start of this). I've learned 2 things since I joined this forum. Number 1, the right holster makes all the difference in the world. Number 2, people are idiots, they don't know what you don't tell them.
Ok, so I started carrying my G19 as my EDC in a N82D or nate tactical.com holster. It's pretty great. Leather for the gun side and sheepskin on the wearer's side. This is a tuckable holster and I've found that if I tuck my undershirt over the gun, I never get questioned. So even if my Polo comes up, the gun doesn't show, but it still prints. As I said before, if you don't say you carry, no one actually seems to notice.
As far as an undershirt between a holster and the weapon, I've also started carrying on the weekends in a kydex holster. Yes,yes,yes, an undershirt against the skin between the weapon and skin is a definite must.