Which nicotine base pg or vg would I want and why? I like a vapor more so I guess, which should I go with for a 60 vg / 40 pg.
Thanks.
If you're buying double strength to mix with doublers, then you'd best
buy the ratio that you like to vape at or which will otherwise work with your doublers. If you're buying highly concentrated nicotine for conventional DIY then you are better off buying it in 100% PG. PG is more stable, up to 2 years at 40C (104F) and will not react with the nicotine even at this temperature. You can store it in the freezer to extend the life by much more. Nicotine in PG is much easier to work with because it's not as thick as VG.
VG is a bit more reactive, and is more likely to have problems with odour/taste depending on the source, and can react with the nicotine over time/temperature.
Source for the PG shelf life is the DOW chemicals advisory.