A representative selection of commonly used 3.05 mm grids. Grid for electron microscope specimen. There are many recipes for preparing good support films. Each EM user generally masters two or three suitable procedures. The nature of the specimen to be examined determines to some extent what type of support film is best to prepare.
Plastic films are easier to make than pure carbon films .
Carbon films are preferred for use in studies where resolution is a critical factor. This leaves a thin layer of plastic on the water surface. The film floating on the surface of the water should appear an even grey to dark grey color when viewed by reflected light. If it appears yellowish or uneven, it is too thick and unsuitable. The grids can then be used as is or they may be coated with an evaporated layer of carbon.