This article will discuss how to choose specific packaging types for specific shipping classes/shipping providers on a fulfillment.
You first will need to create an order and create an ACTIVE fulfillment. More on how to create a fulfillment can be found here.
Navigate to the Create/Edit Fulfillment window,
Navigate to the Advanced tab
Here, you can specify the packaging type that the order will be fulfilled with
Select Save and Close. The fulfillment is now ready to be packed and shipped.