Abstract: Relatively thin flexible sheets of oleophilic, hydrophobic substrates, such as polyethylene film, are used as the basis for sorbent media in novel methods for defending against oil spills. Exhibiting the combination of a high storage density and a high affinity for oil, substrates according to the invention are intended for deployment on sensitive areas of open water or shoreline as a first line of defence against approaching oil slicks, or for early assistance in the containment of oil near the source of a spill. Efficiency and economy in specific applications is achieved on the principle that oil pick-up per unit mass of film-form substrates is increased by decreasing the substrate thickness. The substrate is deployed from a compact supply, in a pre-deployment condition of high storage density onto the area to be protected, in the course of which it is converted to a post-deployment, in-use condition of bulk capacity for oil.