A representative rough surface (panel (a)) that AFM cannot measure. A representative AFM DTM (panel (b)) that is contaminated by adhesive particles carried by the AFM tip. In panel (b), the repeatedly appearing mounds (black arrows) are caused by contamination of the AFM tip with adhesive particles, and the horizontal lines (red arrows) result from the AFM tip scratching across protruding particles. A surface (green outline in panel (c)) apparently resulted from internal breakup of the particle, where a void cavity (yellow arrow) is observed. A smooth surface (green outline in panel (d)) was likely formed more recently, where a fresh fracture (yellow arrow) is visible.