Abstract: A blow molded container comprising a multi-layer laminate wall, said wall comprising a first layer comprising an extrusion blow-molding-capable grade of polymer, the first layer being an inner surface layer of the wall, a second, interior layer, the second layer, a third layer comprising an extrusion blow-molding-capable grade of polymer, and a detectable optical marker embedded in one of the first layer, the second interior layer, or the third layer, wherein said second layer is disposed between said first and third layers. A method of detecting a layer within a blow molded container, comprising shining an incident electromagnetic radiation on a multilayer laminate container, measuring an exit radiation from the multilayer laminate container, and determining if a particular layer having a detectable optical marker embedded therein exists and/or if a sufficient thickness the particular layer exists from characteristics of the exit radiation.