This is a quick activity (on page 2 of the PDF under Butterfly Wings Activity) that illustrates how nanoscale structures, so small they're practically invisible, can produce visible/colorful effects. Learners will use clear water and a single drop of clear nail polish to produce iridescent masterpieces they can take home, permanently displaying the effects of light waves interacting with a film only a few nanometers thick. Also relates to linked video, DragonflyTV Nano: Butterfly Wings.