Straining an oxide membrane Perovskite manganites, such as La _0.7 Ca _0.3 MnO ₃ , have complex phase diagrams with many competing states. Among the knobs that can be used to control their properties are magnetic field and strain. Hong et al. placed membranes of La _0.7 Ca _0.3 MnO ₃ on a flexible polymer layer (see the Perspective by Beekman). Stretching the flexible layer resulted in large strains of up to 8% on the membrane. By varying the magnitude and direction of the strain, the researchers were able to explore the phase diagram of the system and influence its magnetic and transport properties. Science , this issue p. 71 ; see also p. 32