Abstract: The invention is an improvement of the well-known gable top packaging, commonly seen in milk and juice products. The improvement lies in the opening and closing of such packaging with a pull-to-open type opening. This invention addresses the problem that this type of packaging not is water tight after opening. The invention solves this leaking problem by adding a so called zip lock fastener in the opening area of the package. Zip lock fasteners are characterized by having an interlocking groove and ridge that form a tight seal when pressed together. When the user is folding in the pouring spout the zip lock fasteners meet and form a liquid tight joint. The invention is concerning the type and function of the zip lock and its placement. The invention describes as well how to produce gable-top packaging with this new liquid tight zip lock closure.