The author reports the problem of deteriorating sound recording tape, in particular the Ampex range of tapes, both the 6.3 mm and 50 mm varieties. The result of the deterioration is that the tapes are very difficult to run and may, in serious cases, jam in the recorder. The cause is thought to be the deterioration of the polyurethane binder used to hold the magnetic material onto the tape base. The breakdown of the binder is probably caused by hydrolysis of the polyurethane brought about by atmospheric moisture adsorbed onto the tape surface. A method for temporarily reducing the problem so that copy recordings can be made is described.