Propylene glycol (PG) is one of the two ingredients used in the base mix of most e-liquids, along with vegetable glycerine (VG). While VG is often prized for it’s ability to create large clouds, PG is considered more important for intensity of flavour as well as providing a noticeable ‘kick’ to the chest and throat when inhaled, which most vapers find satisfying. High PG e-liquids are very thin and runny and should only be used in MTL vape and pod kits, as they are prone to leak from sub-ohm tanks and pods. High PG e-liquids are often more popular with recent smokers looking for a low-vapour vape juice that provides great flavour and an invigorating lung hit when inhaled.