Fuel cell fluid flow field plate and methods of making fuel cell flow field plates

An electrically conductive, fuel cell fluid flow field plate comprises a first major surface, a second major surface disposed opposite said first major surface, and a plurality of parallel substantially straight channels formed in at least one of the first and second major surfaces. The channels are separated by lands, and at least one of the plurality of channels has an open width less than about 0.75 millimeter. The channels preferably have a length to cross sectional area ratio of between about 2180:1 to about 6200:1. When the fluid flow field plate is used in a fuel cell operating at a current density higher than about 500 mA/cm2, the pressure differential between the inlets and outlets of the oxidant flow field channels is between about 138 millibars and about 400 millibars. Such fluid flow field plates may be formed by embossing or molding.