Magnetic tape consists of a long, thin strip of material (the base), usually of polyester, coated on one side with a binder layer containing very small metal particles that can be magnetised.

To make a magnetic tape, very small metal particles are mixed with a binder, a lubricant and some other ingredients. This mixture is applied as a very thin coating to the tape- which at that point is still a broad tape- it is then rolled flat under high pressure. When dry, the tape is cut into strips of the right width and wound on pancakes and later on spools or in cassettes.

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