Uniform thin films of polymer blends can be produced through spin-coating, which is used as a research tool and on an industrial scale for the production of light-emitting diodes, and more recently organic photovoltaic devices. Toolan et al. present, on page 875, the direct observation of morphological developments during the spin-coating of blends of polystyrene and poly(methyl methacrylate), using their recently developed technique of high-speed stroboscopic interference microscopy. They show that the mechanism by which the final morphology is formed is through domain coarsening when rich in solvent, before vitrification occurs and fixes the phase-separated structure. This study also opens the possibility of introducing feedback during spin-coating, to affirm greater control over morphological development, which could lead to the production of more efficient organic electronic devices.