Filament is best stored in an airtight container to keep out moisture and contaminants. Some manufacturers offer special storage containers that include an airtight seal and space for desiccants.
It is also important to protect the filament from light, heat and UV radiation, as these can affect the material properties. A cool and dark place, such as a closet or shelf in a room with constant room temperature, is ideal.
It is also recommended to dry the filament before use if it has been stored for a long time or if you notice that it has absorbed moisture.
Be sure to carefully seal and store the filament after each use to extend the life of the material and improve the quality of the printed parts.