It's a more common problem than you might think! Typically companies that buy consumer goods from Chinese manufacturers will also entrust that manufacturer to source the associated packaging from their local suppliers.
We all know the importance of the role that packaging plays in driving sales and the above approach can be problematic if they do not have the relevant packaging expertise. Often far less care and attention goes into the production of packaging compared to the production of the product itself. And it's very easy for the consumer associate the poor packaging with a poor product!!!
Accurately profile the packaging requirements (volumes, frequencies & variables)
Consolidate to a manageable number of "best in class" China specialist packaging manufacturers.
Standardise materials and printing techniques
Negotiate improved commercials based on greater volume with fewer suppliers
Negotiate reduced MOQ's for higher volumes reducing stock holding and redundant stock
Apply uniform system for proofing and colour management
Press pass all production runs to raise the bar in terms quality and consistency (which should be less arduous now you have fewer suppliers).