Items, Cases, and Cartons
We support Item units, a case of units, and a carton of cases. You can use the Case and Carton functionalities to avoid committing inventory to any configuration, while still allowing us to ship in bulk without extra pick and pack costs.
Item: one unit of sellable product.
Case: multiple units of sellable product packaged together. You can create a case designation such that when a case is ordered, you are charged for the pick of a single item.
Carton: multiple cases packaged together. Again, you could sell or create an order for a carton—and this would ship with a pick fee of a single item. This is great for wholesale orders or bulk transfers. 
Orders by Item
Inventory is flexible, and if your customers place a large order, the pick and pack fees will automatically be lower.
No additional labels or SKUs are required—just one Item. Orders need to come in unit quantities, as there's no way to directly order a case or carton.
You can find these settings on an Item's Details tab.
Note: you can also reserve inventory by creating an Order for that inventory manually, and pausing the order.
Separate items
This strategy is rarely used because it tends to add complexity for your team. It allows you to reserve inventory for wholesale shipments or ecommerce, and may make more sense to track inventory. Your cases and units will need to be labeled with a separate SKU so they can be scanned.
When using this method, you will have two or three items each with an entirely separate SKU. For example, PINTGLASS, PINTGLASS-CASE, and PINTGLASS-CARTON.
Benefits
There are separate inventory levels for units, cases, and cartons. Stock is automatically reserved as a unit, case, or carton.
Notes
When ordering large quantities, you pay a pick and pack for each unit. If you run out of units, you'll need to contact us to have us break open cases for re-stocking as an hourly Project.
Cases and cartons need to have their own SKU and label
If you would like to track inventory for cases and cartons separately instead of at the unit level, you can create a separate SKU for them and label your packaging accordingly.