A gas turbine article includes a substrate and a thermally insulating topcoat disposed on a surface of the substrate. The surface of the substrate includes a surface pattern defining first surface regions and second surface regions. The first surface regions include incubation sites that are favorable for deposition of the thermally insulating topcoat and the second surface regions are less favorable for deposition of the topcoat. The topcoat includes segmented portions that are separated by faults extending through the topcoat from the second regions.