Comment on "Spin coating epitaxial films".

Kelso et al (Reports, 12 April 2019, p. 166) claim that inorganic epitaxial films were deposited onto single-crystal or single-crystal-like substrates by spin coating. The epitaxial relationships were determined by x-ray diffraction. According to their pole figures, we estimate that each of their films contains only 4.1% to 25.5% epitaxial grains. None of their films can be considered epitaxial.