Abstract: An article of manufacture that has at least three layers of sealable material. There is at least one first seal between at least two of the layers in a first area having a first sealing affinity effected at a first sealing parameter. There is also at least one second seal between at least two more layers, where at least one of these two layers is distinct from the at least two layers joined by the first seal, in a second area having a second sealing affinity effected at a second sealing parameter, where the second sealing parameter is different than the first sealing parameter, thereby allowing for sealing of discrete areas of the article in discrete steps.