Magnetic viewing film is also called Magnetic field display viewing film. magnetic viewing film is used to visualize magnetic fields. It is a translucent paper-like substance which makes magnetic fields visible. Most are made from a plastic film that contains a ferromagnetic slurry of fine nickel particles that align themselves along magnetic field lines. The general principle of operation is that magnetizable nickel particles are suspended in a colloidal form in a gelatinous material. This allows enough freedom for the particles to align with an externally applied magnetic field - thereby displacing the colored fluid and causing a color change at the surface of the film. Recommended for ages 8 and older.