The rosin, as a kind of solvent-free oil, is made by exposing plant materials to high temperature and high pressure. Essentially, the rosin technology is a kind of extraction method involving the use of a heat press that combines both heat and pressure.
There are many ways extracting the golden herbal concentrate, and using a heat press is the easiest one. The principle is that the rosin is extracted by adding a high pressure of gravity at the proper temperature.