a dual bar warp knit , hexagonal mesh fabric for use in hernia repair and to mend other muscle and tissue wall defects , produced according to a back bar pattern chain of 2 / 0 2 / 4 2 / 0 4 / 6 4 / 6 and a front bar pattern chain of 4 / 6 4 / 2 4 / 6 2 / 0 2 / 4 2 / 0 .