The courts at the Australian Open are made of a manufactured surface called Rebound Ace. It is an acrylic surface because irrespective of what's beneath it, what the players stand on is made of ...
In Melbourne Park, the Australian Open was held on Rebound Ace, a cushioned, hard surface. It remained so until 2008, when Rebound Ace gave way to Plexicushion, another type of hard court.