In this image we see how a thin film of copper alloy responds to environmental stresses — curling off the dark plastic substrate below in green daisy-like patterns. This image was taken with an Environmental Scanning Electron Microscope, which allows us to see nanostructures in their native state with extraordinary three-dimensional clarity. ESEM images are originally black and white. But colors can be added subsequently (such as the green in this image) by assigning a given color to a specific gray scale. The material we see in this image is 400 microns wide — about a half of the width of the period at the end of this sentence.