Biscuit packaging bags are folded in half on both sides of the packaging machine, heated and stitched (the extra part on the back of the package, commonly known as "middle seam"), and the end is heated and stitched (the two ends are serrated, commonly known as "end seam"), as shown in the following figure.
The "middle seam" part is not the correct place to open the package. Consumers are more accustomed to opening the package from one side of the product. The serrated "end seam" has the effect of convenient opening. You can choose to open it from any gap on the left and right, which means you can choose the size of the opening. The following figure
I hope it helps you.
The picture is taken from Baidu search; Packaging patterns and pictures belong to Kraft Food Co., Ltd. ..