NOTE: THIS POST IS NOW OUTDATED AS NEW ERA HAS PHASED OUT DIAMOND ERA ON MLB CAPS. New Era is still using Diamond Era caps in Minor League baseball as of 2019. In 2013, New Era introduced a new cap material that they've dubbed "Diamond Era" due to the diamond-shaped pattern in the fabric, which is made of 100% polyester. These 5950 fitted caps have replaced the 3930 stretch-fit caps for both spring training and regular season batting practice. Players had long complained about the 3930s, which have a material that has been described by players as feeling like a "wet towel" once it starts to absorb sweat. They made their debut at the 2013 MLB Spring Training. Several teams also wore them in a few regular season games. Diamond Era caps are made in China, as opposed to normal on-field caps which are made in the USA. However, the patriotic caps made to be worn for the 4th of July were made in the USA (with "imported fabric" according to the tag).