Apart from shipping charges, you are also given the option to charge for handling per box. The "Handling" options in the EZ-Shipping configuration menu allow you to specify handling price per box. Each item in your EZ-Catalog can have a weight value applied to it. The amount of boxes you will need for each order is calculated from this weight value divided among the value you select for maximum package weight. Handling calculations round up to the amount of boxes you will need.
Use Regional Settings to ensure you are using units of weight consitent with your region.
*Note: UPS and FedEx only ships packages under 150 lbs or 68 kgs. USPS only ships packages under 70 lbs or 31 kgs.