When we receive a new mold for proofing and testing, we are always eager to try a good result earlier, and pray for a smooth process so as not to waste time. But here we must remind two points: First, mold designers and manufacturing engineers sometimes make mistakes. If we do not increase our vigilance when we try the mold, we may cause big damage due to small mistakes. Second, the result of mold trial is to ensure smooth production in the future. If reasonable steps and proper records are not followed during the mold trial process, the smooth progress of mass production cannot be guaranteed. What we emphasize more is that "the successful use of the mold will quickly increase the profit recovery, otherwise the cost loss caused will be more than the cost of the mold itself."