Sputter coating

Vacuum-deposition technique that lays a thin (5 to 15 nm) conductive layer of gold, gold-palladium or carbon onto a non-conductive sample (polymer, biological, fibre, dried biological) so that the primary electron beam does not charge up the surface and destroy the image. The coating is what lets you image a paint chip, a human hair or a polyester fibre in a conventional SEM.