There are four main categories in the BSTI:
Your skin will fall into one of the two categories, and you'll have four letters indicating your skin type. Right now I feel like I'm an oily-sensitive-pigmented-wrinkled or OSPW!
The BSTI isn't the end all and be all of skin type assessments - for instance, what about normal skin? - but it does offer an interesting framework for thinking about our skin and how to formulate for various types!
So let's start with the dry to oily skin type!