Answer:it's not coating properties it's magnetic properties
and it is electrostatic charges
Videotape is all about <u>magnetic</u> recording. First introduced commercially in 1956, magnetic recording was a relatively new technology. Videotape and all other forms of recording tape are the same in that they are magnetic. Videotape, in fact, is very similar in composition to audiotape. Most videotapes consist of a layer of tiny magnetic particles applied to Mylar, a strong, flexible plastic material. About a billion magnetic particles cover a square inch of tape and function like microscopic bar magnets. When the tape passes over an electromagnet, information is recorded and played back.
The magnetic particles are the most important part of the tape, as they are responsible for picking up and carrying the video signal. Particle size, composition, density, and distribution determine the quality of a tape. During the manufacturing process, the particles are arranged in the tape's coating. During the recording process, video heads arrange the particles into patterns dictated by the changing voltage of the video signal. When the tape is played back, the patterns are picked up by a playback head and become the video image.
Today's magnetic tape is composed of three main layers: the base film, the magnetic layer, and the back coating. The base film provides the physical support and main strength of the tape. Base film consists mostly of Polyethylene terephthalate (PET) because it is durable and resistant to stretching. The magnetic layer determines the tape's magnetic properties. It is composed of magnetic powders, ranging from lower strength iron oxides to high-energy metal particles, that determine the tape's magnetic properties; binders that provide structure to the layer, including polymers, adhesives, lubricants, cleaners, solvents, dispersion agents and <u>static controlling compounds;</u> additives, such as carbon black, that enhance tape properties; and lubricants, that decrease friction and wear. The back coating, which is made up of lubricants, enhances the tape's durability and performance.
