Plant or Carrier oils are Vegetable oils. They act as carriers for the essential oils, and allows them to spread over a larger area of the skin. It is recommended that carrier oils are used to dilute the essential oils before they are used on the skin. Vegetable oils are the best carrier oils because they are moisturizing and are plant based. They are much better for use instead of mineral oils. They should be stored in a well sealed container out of sunlight, and in a cool place to prevent rancidity. Common Vegetable carrier oils are Sweet almond, Grapeseed, Jojoba etc.