Vegetable Glycerin (VG) and Propylene Glycol (PG) are the two base ingredients required for making eJuices, usually in conjunction with Nicotine and Flavourings. They are mixed together in different ratios with a more VG-based liquid (70%VG & 30%PG) being thicker, and a PG-based (30%VG & 30%PG) being thinner and runnier.
Vegetable Glycerin is a naturally occurring liquid, derived from plant oils, and occurs in many every day items. Propylene Glycol is a liquid used frequently in food processing and medication. Both have widespread uses in our modern lifestyles, and can be found in many industries and products, including vaping and eLiquids.