This study examines the influence of in-flight particle properties and substrate temperature on the quality of ceramic layers obtained at atmospheric plasma sprayings. Investigators sprayed aluminum oxide and zirconium dioxide powders on metal substrates, using infrared temperature measurement techniques to monitor the process. The authors present the test data and explain what it reveals about particle flattening behavior, coating morphology, and the effect of cooling. The investigations show that the influence of substrate temperature must not be overlooked if layer properties are to be predicted and controlled. Paper includes a German-language abstract.