A battery separator embossed with a configuration that is neither vertical corrugation or vertical rib and yet in which all of the surface areas of the two separator faces open or slant upwardly except the portions actually directly engaged against a battery plate. Thus all intended recesses in the faces of the battery separator are open at their upper extremity so that no gas can be trapped by the configuration of the battery separator embossment. Additionally the division portions between the embossed recesses on the positive plate engaging face are in continuous engagement with the positive battery plate from the bottom of the plate to the top of the plate which provides stability to the raised areas of the battery separator that engage the negative battery plate.