AbstractWe Have Measured Directly The Forces Between Two Smooth Solid Surfaces Immersed In Liquid Media In The Range Of Surface Separation 0 ∼ 2000Å. By Measuring The Interactions Both With And Without Polymers Adsorbed Onto The Surfaces From The Solution, We Could Characterize The Effects Due To The Adsorbed Polymers Themselves. This Has Been Done For Several Model Polymer Systems In A Wide Range Of Solvency Conditions: Poor‐, Theta‐ And Good Solvents, As Well As For Charged Polymers In Ionic Media. The Present Paper Describes Two Recent Studies Of Adsorbed Polymers In Theta‐Solvent And Good Solvent Conditions, And The Effect Of Polymer Bridging At Low Adsorbance Values. The Experimental Studies Are Extremely Direct, And Can Be Compared With Molecular Models: We Briefly Describe Such A Detailed Comparison For The Case Of Interaction Between Adsorbed Polymer Layers In A poor