Fig. 3From: Detecting iron-based pigments on ruthenium-coated ancestral Pueblo pottery using variable pressure scanning electron microscopyTescan Vega 3 XMU SEM secondary electron image of ruthenium coated sherd at a vacuum of 2.1e−2 Pa. A Tescan Everhart–Thornley secondary detector (without a turbo-molecular pump) is used for this image. Tabs of carbon tape (arrows) added to locate area of sample. Bright areas on image are caused by charging. Scale 2 mmBack to article page