The invention relates to a fluid composition intended to form a dressing on the skin. The composition contains: 6 - 12 wt.-% of a cellulose derivative, 5 - 15 wt.-% of a vegetable oil, and a volatile solvent. The oil/cellulose mass ratio is between 0.8 and 1.5. This novel dressing base can be used to produce a film on the skin that provides satisfactory water and friction resistance. The film is flexible and sufficiently comfortable, particularly when the dressing is applied to a reasonably large area of the skin.