My son & I got into a debate over this, when he was here visiting last March. He told me the decorative side goes up so you can see the pattern - and I told him no - you put your glass on the flip side, where the cork or felt side is: that's the whole point of using a coaster - to capture the moisture. What good is it gonna do, if you don't use the side that captures the moisture?!
Sometimes I think they switched babies on me at the hospital..
Which side do YOU use??