Sample processing devices that include transmissive layers and control layers to reduce or eliminate cross-talk between process chambers in the processing device are disclosed. The transmissive layers may transmit significant portions of signal light and/or interrogation light while the control layers block significant portions of signal light and/or interrogation light. Methods of manufacturing processing devices that include transmissive layers and control layers are also disclosed. The methods may involve continuous forming processes including co-extrusion of materials to form the transmissive layer and control layer in a processing device, followed by formation of the process chambers in the control layer. Alternatively, the methods may involve extrusion of materials for the control layer, followed by formation of process chambers in the control layer.