Glass bottles are relatively stable and do not easily react chemically with essential oils. The plastic bottles like ordinary plastics, including some plastic bottles, are not ideal. Some essential substances are easy to be precipitated when the essential oils are contained, because some essential oils are highly volatile and the molecular structure is not very stable.Use dark glass bottles to prevent some essential oils from reacting lightly.Therefore, we only use brown glass bottles for oils. It is convenient to prepare 10ml for the face and 30ml for the body. The concentration of the face and body is different.