Why can a carton look poor at the score even when the flat print looks good?

A flat proof has not been creased, folded, rebounded or glued. Where solids, reverse type, codes, foil edges or spot treatments cross a score, inspect them on the actual carton structure. Put those elements on one proof, convert it through the real process, and check first fold and repeated opening. Revalidate after a stock, structure or coverage change.