We've all had this problem. The roll of masking tape in the garage has been sitting around for several years, through winter and summer. We desperately need to use it and now, when we start to pull a strip, it comes off in shreds or tears along its length. It's nearly a full roll and it seems to be useless. Besides, now we'll have to go buy another roll or find a neighbor who has some.
Don't run off just yet! There's probably some hope for that stiff, aged roll of tape. Take it into the kitchen and place it in the microwave oven. Give it 30 seconds (no more!) on High and take it out when the buzzer sounds.
How is it now? Can you tear off a length without problems? Chances are you can, since you've "rejuvenated" the adhesive with microwave energy. The tape should stay in good shape for quite a while afterward, and you can repeat the "treatment" several more times before you cook the adhesive forever.