In my business, each product has both a carton quantity and weight quantity. The items are stored and transported in cartons and the weight is used to calculate the price. Some items have a set weight per carton while others fluctuate.
How do record both these quantities for an item and input both in an invoice or purchase order? Further how do I allow differences in weight for the items that do not have set weights?
Basically I'd like the customisations to produce invoice lines like this.

Any ideas would be helpful. Open to suggestions on coding or other add-ins/implementation providers that can help do this