VG/PG stands for the two main components that make up vaping liquids, Vegetable Glycerin and Propylene Glycol. Vegetable Glycerin is a natural compound that is derived from vegetable oils and is a thick substance. Propylene Glycol is an synthetic compound that is often used in food products, PG is a relatively thin substance. The different rations of VG and PG can create different viscosities of e-liquids.

Two of the most common ratios of VG and PG in E-liquids are 50/50 VG to PG, which is a thinner type of liquid and 70/30 VG to PG which is a thicker type of liquid. There are many other ratios but these two are the most common.

When choosing what type of E-liquid is best for you it is important to know what device it is that you will be using it in. Thinner liquids are always better for lower powered Mouth-To-Lung devices and thicker liquids are always better suited towards higher powered Direct-To-Lung devices. 

50/50 E-liquids are an example of a thinner liquid ratio that would be more suited to lower powered devices, this is because the lower powered devices often have smaller coils and the thinner liquid is needed to absorb properly into the coil. Using a thicker liquid on these coils could make your coils burn out quicker than you want them to.

70/30 E-liquids are an example of a thicker liquid that would be more suited to higher powered devices, this is because the bigger coils on the high powered devices are able to absorb the thicker liquid due to them often having much bigger wicking holes. if a thinner liquid is used on a more powerful sub-ohm device it could cause liquid to absorb too quickly which could result in leaking issues.

Other than the two main ratios being 50/50 and 70/30 there are also other liquids that use other ratios of VG to PG, an example of this could be a 60/40 VG to PG liquid, this type of liquid as you can imagine would be half way between the two previously mentioned ratios in viscosity, this type of liquid could be more suited towards a restricted direct to lung device that power sits somewhere between a sub-ohm device and a low powered mouth-to-lung device.

For a general rule of thumb, the lower the ohm of the coil the thicker the a liquid it would be suited for, and vice versa, the higher the ohm of coil the thinner a liquid it would be suited for.

To learn more about the different types of devices click here.