The only disadvantage is time. Since dewaxed varieties are the most processed, their shelf life is about 2 years from the date of manufacture. Therefore at ShellacFinishes all our shellac has an expiration date. The date is merely an indicator and not to be taken as an end date. If shellac is used after this date, make sure that it dissolves completely in the alcohol. If you see a thick gooey gelatinous mass at the bottom of the jar, its past its shelf life and should not be used. It is always a good idea to buy shellac flakes as and when required.