Background <p>This work is dedicated to Professor Cesar Sciamarella for his contributions to Experimental Mechanics on his 100th birthday.</p> Objective <p>We introduce an experimental framework that enables characterization of micro-slip friction behavior in quasi-static rough surface contact.</p> Methods <p>We utilize high-resolution displacement-field measurements with electronic speckle pattern interferometry (ESPI) and employ physically guided digital data processing, facilitated by equilibrium smoothing. This approach allows for the characterization of mesoscale interfacial contact and slip zones. Our verification experiments utilized an innovative end-loaded split (ELS) test apparatus to investigate microslip processes in PMMA contact interfaces.</p> Results <p>We observed an apparent interpenetration of contact surfaces that follows a power-law relationship between the normal contact stress and the apparent penetration depth. This apparent interpenetration is attributed to an interfacial roughness layer (IRL). Under combined normal and shear loading, we measured a slip precursor of about 3&#xa0;microns—known as the Dieterich characteristic slip distance—before macroscopic slip.</p> Conclusions <p>This experimental framework broadly holds potential for a wide range of studies in contact mechanics and tribology, including interface adhesion, cold welding, and fretting wear. It may deepen our understanding of rough surface interactions.</p>