Testex is the manufacturer of Press-O-Film replica tape. Press-O-Film provides inspectors and researchers a simple way to obtain an impression of a surface. Press-O-Film (POF) consists of a layer of crushable plastic microfoam coated onto a polyester film of highly uniform thickness. When compressed against a roughened material, Press-O-Film accurately replicates details of its surface roughness. The impression can be studied in either of two ways: 1. A simple micrometric dial thickness gage can be used to determine the average maximum peak-to-valley roughness, or "profile," of a replicated surface, or, 2. An optical profiling interferometer or similar device can be used to produce maps of the replica's surface topography. This is most appropriate to study of subtle features at the microinch (25 nanometer) level.