The instant invention is directed to a sheet product capable of forming an improved battery separator. The present sheet product is formed from a thin, acid-stable, porous material and has a first and a second major face with a plurality of separate, continuous, open channels on each major face such that each channel on each major face defines a separation between two channels on the other major face. Further, each channel defines an imaginary median line with at least some portions of at least some channels extending laterally with respect to the imaginary median line and each channel has at least one continuous contour line in the form of straight line segments such that every portion of each channel is capable of being at an acute angle of not greater than 70 degrees from an imaginary vertical line orientated from bottom to top of a battery containing the sheet product.