Abstract: A fixture for depositing a gradient coating includes a single opening on a front side of the fixture, such that the fixture is configured to house a substrate during deposition of a coating and configured to surround the substrate on all sides of the substrate except for a single front side of the substrate, and wherein the fixture is configured to restrict egress of coating material to the substrate from all directions except through the single opening. The fixture includes a cavity such that the fixture is configured to leave an air gap between a lid surface of the fixture and the major top side of the substrate, and a cavity depth, measured from the front side of the fixture to a back of the cavity, is greater than a gap opening distance, measured from the lid surface at the opening to the major top side of the substrate.