To print the weight information of the document pulling the weight information from the product entities (item master), you need to add this xxxTOTALS_WEIGHTxxx in your custom footer/header in the printouts of the document templates.
To print the weight information of the document pulling the weight information from the document rows (this assumes the weight column is present in the document rows), you need to add this xxxTOTALS_WEIGHT_DOCUMENT_ROWSxxx in your custom footer/header in the printouts of the document templates.
To print the weight information of the document pulling the weight information from the document itself, you need to add this xxxTOTALS_WEIGHT_HEADERxxx in your custom footer/header in the printouts of the document templates.
