Storing cannabis properly is important to preserve its freshness and potency. Plastic bags are not the best option for keeping weed, as they can let in air, light, and moisture, which can degrade the quality of the cannabis plant. Mason jars are a better alternative, as they are airtight, dark, and durable. To store weed in a mason jar, make sure the weed is dry and cured, fill the jar about three-quarters full, and keep it in a cool, dark, and dry place.