Provided is a method of patterning a substrate. The method includes depositing, in a first predetermined pattern, hydrophobic material on a first surface of a hydrophilic substrate. The method includes permeating the hydrophobic material through a thickness of the substrate without reflowing the deposited hydrophobic material. The method includes sufficiently solidifying the permeated hydrophobic material. The sufficiently solidified hydrophobic material forms a liquid-impervious barrier that separates the substrate into at least one discrete region.