Such technologically dependent products may not work in the future. Even at room temperature, magnetic videotapes have an expected shelf life of only 20 years. CDs are expected to last only 50 years. Photos are good. So are letters.
Newsprint tends to break down.
So does rubber or thin plastic. Although you can buy specialty capsules on the Internet, people often use whatever they can find around the house, Hudson said, including Mason jars, Tupperware, pop bottles, plastic bags and cookie tins. He's even heard of coffins being used for time capsules. Truth is, you can use just about anything. As long as it's dry, dark and durable.