There are three types of regular containers used for potions. It was a grade to third-grade container. The difference lies in the transparency and thickness of the bottle. The first-grade container uses uniform glass, and the way the light enters is stable.3 The degree of light entering is important, and it is said that it is easy to discolor when unstable. Many people whose potion-making skills still lack or produce unstable potions mostly use third-grade containers. In fact, those who make unstable potions are recommended to use first-grade containers. Still, if they use it and the potions are discolored, they wouldn't be able to sell them as degraded versions, and the price of the containers would make them in the red. No one is using first-grade containers because it would be a hard blow for them. Now, the first-grade container is proof of high quality.