In response to the fact that the ingredients of the UV gel nail polish must be isolated from ultraviolet rays, and there are different color requirements for the outlooking of the bottle in the market, the nail polish bottle needs to be treated with different colors of baking paint on the appearance of the bottle. However, after multiple processing to achieve the coating, the coating effect often increases a lot of costs and defect rate. After many studies and adjustments, we found that adjusting the color density of the paint itself can be practical in one or two baking paint processes without affecting the adhesion, to achieve the successful result.