GI-SAXS samples: glycerol, Brij-56, cithrol, phytantriol and the MO/DOPS/CHOL mixtures were each dissolved in 80% (w/w) ethanol and mixed in different volume ratios to give an overall 80% (w/w) ethanol solution which was used for spin coating on substrates. The volume ratio of the different ethanolic solutions mixed together is therefore approximately equal to the mass ratio of the different lipid / surfactant / glycerol components on ethanol evaporation during spin coating, quoted in the main text. The wafer substrates with lipid thin films were placed within an environment chamber filled with either humidified argon (ESRF) or helium (Diamond Light Source) which was constantly at between 70 and 95 % humidity.