There is a "shelf life" of knee high panty hose? I found that out this morning when I took a pair out of my dresser drawer this morning. I have no idea how long I've had them, but when I put them on, the elastic band at the top of the knee high just crumbled. Elephant ankles wasn't the look I was going for, so I had to run to the store BEFORE 7 a.m. to get some more! And I thought I was prepared to go back to work!