What is eLiquid?

eLiquid can contain these five components:

Vegetable Glycerin (VG) expressed as a percentage.

Propylene Glycol (PG) expressed as a percentage.

Nicotine expressed as weight per volume often referred to as Nic strength often indicated only by milligrams (mg). The "per milliliter is assumed".

Distilled Water to lesson viscosity, enhance steeping or mellow the taste though it is not typically used.

Flavorings such as Banana, Pumpkin Pie, Cotton Candy, Chocolate, etc.

For example a bottle of eLiquid called Dragons Blood might say 70/30 18mg. The 70/30 is percentages of VG (70) and PG (30). The 18mg refers to 18 milligrams per milliliter of nicotine. The "Dragons Blood" refers to whatever ingredients were used to create the flavoring someone deemed "Dragons Blood".

Not all eLiquids contain nicotine, those that do not are typically marked by 0mg or 0nic.

Not all eLiquids contain PG, those that do not are referred to as 100VG. Not all atomizers work as well with 100VG due to its viscosity*.

I suppose it is possible to have 100PG eLiquid.

VG is thick and somewhat sweet tasting. It creates large amounts of vapor. Propylene glycol is less viscous and tastes even sweeter than VG. PG is used to enhance throat hit and thin the eLiquid. If you don’t like PG and need to thin your 100VG juice then use a few drops of distilled water. The water will change the taste. Too much and the vape gets “steamy”! So I only used a few drops. Also water will evaporate faster than the VG so I wasn't surprised when the water was gone in the morning. A little bit of water goes a long way. As shown in the table below VG is an order of magnitude more viscous than PG, and water is much less viscous by several orders of magnitude than PG. That is why high VG doesn't work as well in tanks.

Some people are sensitive to PG. Typical issues with PG are sore throat and dry mouth. Since VG is thick, too much vapor and lungs may get congested. For myself, I have no issues with VG as long as I keep the power reasonable and found PG an unnecessary complication and risk.

I will go into detail about the safety research I performed of these components in "Are eCigarettes Safe?". Suffice it to say that the big unknown in eCigarettes and vaping are flavorings. Flavoring manufacturers are not required and do not list their ingredients.

In order to save gobs of money and control the risks of vaping, I make my own eLiquid. This is discussed in "DIY eLiquid".

*Note: VG is much more viscous (thick) than PG or water. In fact it is more dense and more viscous than 30W engine oil.
Density of 30W motor oil ~.875 g/cm3
Density of Vegetable Glycerin ~1.26 g/cm3

Dynamic Viscosity


(Pa s) @ 300K/80F/26.85C

factor of 30W motor oil
Vegetable Glycerin


Propylene Glycol .042 x.25
Water .00089 x.005
30W motor oil ~.17 x1

I have seen videos on youtube of “High VG” showing bubbles rising in the Kayfun V4 with glass tank middle section. What struck me was how fast the bubbles rose in that video, a second or two. I don’t know what “High VG” they used but I can say my bubbles take 6 to 10 seconds to clear the glass section and sometimes get stuck in the bottom and don’t release until I tilt or shake it. Sometimes I have to completely up-end the atty to get the air bubbles to release. That is the difference between “High VG” and “100VG" that I run which is low moisture content 100% VG. The high viscosity and surface tension makes some attys friendly to 100%VG and others not so much. It is not so much a matter of juice flow as it is reverse flow of air back into the tank. The draw creates a vacuum at the juice channel openings in the build deck area. But there is another vacuum being created at the top of the tank. This vacuum holds back the juice flow and only reduces when air bubbles are released back through the juice channels into the tank. There are some tricks to help this. On the Kayfun V4, I drilled the small juice channels to 1.6mm and that helped. On the Kayfun V4 plus 28mm, drilling the juice holes to 2mm helped even more. I will annotate what modifications I made to my tanks necessary to specific attys in the "RTAs" to help them be more 100% VG friendly if needed. But all RTAs will see increased juice flow and reverse air exchange with a lower viscosity juice.

There are those that believe "high VG" is anything with less than 50% PG. There are those that believe high VG performs better in "sub-ohm" tanks or drippers. There are those that believe "cloud chasers" use high VG. And there are those that believe VG causes high blood sugar. And there are those that believe high VG is for high power. There are those that believe high VG is bad. And there are those that believe high VG is destroying the industry. I found these are all incorrect at best. So called "high VG" is anything over 70%VG. High PG works better in ALL tanks, sub-ohm or otherwise. High VG by anyone's definition is used by flavor and cloud chasers, open draw and MTL. I am diabetic and talk about the blood sugar issue on my Are eCigarettes Safe? page.




All the information contained in these pages are only the opinions of the author and the author is not an expert at anything.