If this tracking path isn't precisely followed when the tape is played back, the resulting tracking errors can produce unstable images. The ratio of usable signal to undesirable noise in a black and white picture. This refers to the decomposition of an acetate based magnetic tape layer. It causes the tape to smell like vinegar and results in a faster loss of the backing. The tape should be evenly wound onto the reel, with no high or low areas, and with an even tension, so the tape is not tight in some areas and lose in others.
Pack slip refers to uneven winding.