The national standard GB / T8946-1998 stipulates that "flatten the bag, enclose the two squares of 100mm x 100mm at the upper and lower diagonal corners of the bag, and the outer edge of the square is 100mm away from the edge of the bag. , Take the average value, when counting, when the last point is less than one, it is counted as one. "The national standard stipulates the density of weaving, and specifies the density tolerance. The weaving density mainly depends on the packaging product and is determined by the user.