Fin Materials

Molded Fins
Molded fins are manufactured using a composite mix of materials. Most of these fins have more flex. At this time, molded fins are the most common. FCS refers to them  as Glass Flex or Composite. Future calls them Natural Composite or Composite.
Fiberglass Fins
Similar to old glass-on fins, layered fiberglass fins have a solid flex. The base is stiff with more flex at the tip. These are most popular for surfers who want to re-live the throw-back performance of glass-on fins. They also enjoy the ability to remove these new fines  and swap out other designs. Futures refers to their fiberglass fins as simply fiberglass. FCS likes the more sophisticated Performance Glass (PG).
Resin Transfer Molded Fins
The most high tech fins use RTM construction which utilizes high technology that began in the aerospace community for flight. Glass is  sandwiched with layers of honeycomb foam which creates a super-strong, very light, waterproof material. RTM fins are the best-sellers due to their high performance, strength, light weight and high tech appearance. There FCS refers to Performance Core (PC). Futures labels  them RTM or HEX.