If you work with returnable packaging, we recommend that you create two products in the administration with a positive and a negative amount. For example, returnable packaging worth 50 CZK and -50 CZK. As soon as you sell the returnable packaging to the client, you will mark the product with a positive CZK 50 amount. When returning the returnable packaging, you choose a minus product of CZK -50 and return the deposit of CZK 50 to the client. If you use our warehouse management, do not forget to connect the returnable packaging product with the warehouse card.