Acetate tape buffered by cardboard box

I have been suggesting for many years that one of the reasons that acetate audio tapes have not suffered from vinegar syndrome to the extent that acetate films have suffered from this malady is because of differing storage practices. In general, film for many years was stored in sealed cans while tape has generally been stored in cardboard boxes.

I recently came across a 3-inch reel of acetate tape, not in its original box, that showed the following pattern in the box. This tape was recorded in Fall of 1964 and the photo was taken on October 2006, 42 years later. The tape played well, considering it was originally recorded at 1.88 (1-7/8) in/s.

Box discoloured by acetate breakdown products

All of the outgassed material that was absorbed by the cardboard was no longer free to degrade the tape.