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Application Note for Leica EM RES102 – Mechanical polishing of soft materials or hard / soft material combinations is tricky. The mechanical polishing process leads very often to smearing of the soft material. The smeared material covers the surface and fills small pores or holes. Grain structures, interfaces and other structural details can be masked. An additional ion milling step with milling angles between 10° C and 15° C with respect to the sample surface can remove or reduce the contamination.