Wikipedia
Laykold
Laykold is a tennis hardcourt constructed over an asphalt or concrete base. It can be constructed without cushion or with a cushion layer (Laykold Cushion Plus) for better force reduction and longer player longevity. Court surfaces are made of various materials including rubber, silica, and acrylic resin. Laykold is manufactured by Advanced Polymer Technology, based in Harmony, Pennsylvania.
Laykold is currently the surface of the Miami Open.