Mixing with correct ratio and method is essential for a good cure result.
Top coat resin and flexible resin is simple 1:1 mixing ratio. All other types of resins are 2:1 (200ml part A and 100ml part B). It is recommended to mix by volume and not by weight. Make sure 2 parts are mixed gentally and thoroughly in a plastic/silicone cup, scrap the sides/edges of cups too. During mixing process you would notice the consistency changes from "thick and cloudy" to "water clear".