The ultramicrotome is an instrument commonly used to prepare TEM samples. It uses either a glass or diamond knife to cut ultra thin sections of specimens embedded in epoxy. The sections are approximately 60 to 100 nanometers in thickness and 0.5 to 3 mm in width and can be stained and mounted onto TEM grids for viewing. The ultramicrotome is also used to create mirror-smooth surfaces on samples mounted in epoxy, the applications for which include secondary imaging on the SEM and nanoindentation. Preparation on smooth samples for surface analysis need not always be of samples that are embedded, as sometimes bulk will work.