What is the difference between PG and VG liquids?
Propylene glycol (PG) is a petroleum based liquid while vegetable glycerin (VG) is made from vegetable oil, usually palm or coconut. PG has a natural bitter taste and needs flavorings to cover it while VG has a natural sweet taste and can be used without any additives. VG has a much thicker viscosity and requires another liquid, usually water, to reduce it.