The polymer-induced repulsive interactions between the surfaces of a l
iquid film are measured for two systems using two force measurement te
chniques, in the case where the polymer is in a good solvent and adsor
bs at the liquid surface. The force decays exponentially with the film
thickness with a decay length proportional to the radius of gyration.
The data are compared with a recent theoretical work which predicts a
repulsive exponentially decaying force at large thicknesses.