soap film

A term established by usage for A/W/A films stabilized by surfactants although it is not a film of soap, nor is the stabilizing surfactant necessarily a soap. (A/W/A means water film in air).
Source:
PAC, 1972, 31, 577 (Manual of Symbols and Terminology for Physicochemical Quantities and Units, Appendix II: Definitions, Terminology and Symbols in Colloid and Surface Chemistry) on page 613