||The primary catalysts for the decomposition of LSD are heat, light, oxygen, and moisture. LSD's shelf life can be significantly extended if exposure to these are minimized.|
Air & Light
Keeping LSD in an air and light proof container is the most important step. A good option is a dark amber glass container kept somewhere cool. Remember, most plastic (plastic bags) is not air tight, though it's a lot better than nothing. Likewise, keeping blotter in foil isn't going to stop air transfer, but it's also better than nothing. If glass isn't available, a combination of foil and plastic would be more effective than either one alone.
LSD will degrade even at room temperature, but the hotter the temperature and the longer it is stored in a hot location, the more it will degrade. At room temperature, degredation is quite slow, so a cool room, out of the sun is generally enough to minimize break-down. Storing blotter in the refrigerator or freezer is fine, but is probably unnecessary.
If blotter is stored somewhere cold (as opposed to cool), it should be allowed to return to room temperature before being opened as this will prevent condensation from forming. Also, if the weather is extremely humid, storing LSD with a little bit of dessicant (drying agent), can ensure that it stays dry.
If these storage methods are followed, blotter should last for many years. Foil in the freezer is a common storage method, and should be effective at keeping degradation to a minimumfor a few years.