Top coats and base coats are completely different formulations that are designed to do different things. Base coats need to have good nail adhesion, while top coats must have hard surfaces with good scratch resistance. Ingredients with good adhesion are usually softer and stickier, so they don’t make good top coats. Ingredients that have hard, scratch-resistant surfaces create slick surfaces that won’t adhere well to the nail plate.
If the manufacturer of the builder gel directs that you should use a particular top coat, you should always follow the directions and use products as they were intended to be used. Don’t mix-and-match products that were not intended to be used together. Cherry-picking products is basically ignoring directions and should not be done. One of the biggest problems in the nail industry is that too many techs make up their own directions and use products in an inappropriate fashion. It may “seem” to work, but there are often unintended consequences for ignoring directions.
— Doug Schoon, industry scientist, author, and educator