Q&A: How do we use solubilizers? Do we need them in products that already have an emulsifier?

In the monthly Q&A, Kara asked, Hi there! I am trying to learn more about the chemistry of creating body products, and I have a clarifying questions on emulsifiers vs. solubilizers. Based on my reading here, it seems like solubilizers are used in a water-based product for small amounts of oil-based things such as fragrance…