Progressive cracking of a 100-nm thick ITO film on 100- m thick polyester substrate during tensile loading (along the horizontal direction). Unloaded ITO (a); at 1.28% strain (b), the arrow indicates the failure initiation on a coating defect); at 1.42% strain (c); and at 3.42% strain (d). Density of tensile cracks and normalized resistance change during tensile loading of 50 nm (solid symbols) and 100 nm (empty symbols) thick ITO (e).^[163]