"Normal juice" tends to have a higher PG ratio such as 70%PG / 30%VG, whereas the more "premium juices" tend to be high in VG and are a lot thicker due to the gloopy consistency of VG, whilst PG is more watery. MTL devices work better with higher PG juices and sub-ohm atomisers would need to be used with a higher VG e-liquids. you can read more about it by visiting our E-Liquids - The Bottled Secrets blog.