The proper storage of thermoset materials is key to maintaining optimum processability. Thermoset materials have a theoretical shelf life as determined by standardized laboratory measurements. Shelf life is affected by ambient temperature and is also dependent on the parameters and latitude of the molding process, along with tool and part design. As a result, actual shelf life may vary, perhaps significantly, from the theoretical shelf life for the material. Change in flow characteristics during the storage of material does not occur suddenly, but gradually over a period of time.