an improved , easily openable rectangularly - shaped container for liquids such as milk and juice formed of folded sheet paper or plastic , the improvement comprises the addition of an opening device having a first portion connected to the sealed pour spout and a second position integral with the first portion which extends free from the pour spout adapted for hand grasping . the first portion , when the second portion is pulled away from the pour spout , separates the sealed mating upper margins of the pour spout . the improvement may also be detachable after initial opening of the container .