A method for assembling a fin seal container including folding a container blank into a three-dimensional body that defines an internal volume and includes an end portion that defines an opening into the internal volume, the end portion including a first fin seal panel having inner and outer major surfaces and a second fin seal panel having inner and outer major surfaces, folding the end portion such that the inner major surface of the first fin seal panel is positioned adjacent to the inner major surface of the second fin seal panel, separating the first fin seal panel from the second fin seal panel, treating the inner major surface of the first fin seal panel and/or the inner major surface of the second fin seal panel, and pressing the first fin seal panel into engagement with the second fin seal panel.