A method of manufacturing a substrate configured to be wetted by a device internal to the substrate. The method includes a roll to roll processing method using two different plies to form a substrate incorporating a latent wetting device. The method includes forming a container by creating a vessel in two parts. One part is formed on a bottom ply and another part is formed on a top ply. A wetting agent for wetting the substrates is added to one part of the vessels and the plies and vessel parts are joined using a continuous manufacturing method.