Latex is made from tiny polymer particles in water. Latex films are used in paints and to manufacture adhesives & inks. Latex is good for the environment, as it does not emit harmful organic solvents and meets strict EC regulations. Usually latex contains a type of soap molecule (surfactant) needed in its manufacture. Sadly, the surfactant is the source of problems in latex films, allowing water to absorb and leading to corrosion of underlying surfaces, eg steel. A new type of latex, developed in Lyon, is made with specially-designed molecules attached to the polymer particles, which eliminate the surfactants. We propose neutron scattering to “look inside” a wet latex film as it dries to see the fate of the stabilising molecules. It will also reveal where water goes when absorbed inside a dry film. This will lead to eco-friendly coatings that will block all water from passing through.