For each board, ensure 50%~60% clean(no waterline/knot/blue stain/cracks)， but the rests allow waterline , knots ,cracks ,ending crack allowed.

每一块板材，两个大面允许出现节疤、水线、开裂，剩余干净面{无水线、无蓝变、无节疤、无开裂等木材缺陷}可达50%~60%，允许端裂。