Back in the old days, only seedlac and buttonlac was available. The process to make these are still carried on today. Seedlac is the shellac that has been removed from the twigs, cleaned and sieved by hand. Buttonlac is made from the cleaned seedlac by pushing it through a muslin cloth held close to a charcoal fire. Both these varieties contain wax, which is a by product of the lac insect. Unfortunately wax is not the wood polishers best friend. When amalgamated with shellac, it makes the finish porous and facilitates reaction with moisture. Ever heard about stories of a white ring forming if a cold glass of water is left for long over a shellacked surface? Well, it’s the wax in the shellac that helps in the creation! Therefore always decant waxy shellac varieties many times to remove as much wax as possible. Shellac without wax will have superior adhesion and water resistant qualities.
But consider yourself lucky that due to technology, you don’t have to go through the decanting process. Dewaxed shellac is now available!! The wax content of this variety is between 0.2-0.5%. This is the very reason why I strongly recommend using dewaxed shellac. Whether you are using it for a an antique or for a new finish, it matters little. It is available in different colors and if not, it can always be colored with aniline dyes to suit your taste.