What matter of sorcery is this!? I bought one of these shirts for a wedding I was in. It was an outdoor wedding in Florida and we were wearing long-sleeves shirts in a color that would clearly show sweat stains. I didn't want to have sweat stains in all the photos, so I bought this. HOLY-COW....somehow this thing worked amazingly well. I will be purchasing a couple more to wear exactly for occasions where I don't want to show any sweat.