I absolutely love En Vogue. It's great product and very easy to use. They have an introductory course for those whom are already nail technicians to learn about En Vogue and all the different techniques they have for $100 Canadian. You really do not need to take the course its that simple to use. There is no discoloration, its nice and strong. If the Modeling Resin is to thick though it will heat up in the UV light and be extremely hot!! More than usual I found. I honest love the product line. They have a drop kit which includes their connector, modeling resin, french modeling rein, and their sealer with their prep and clean solution for $60 Canadian to try.