In Magento/Zoey you can ship in master packing boxes for a particular SKU. These boxes are used in preference to the ‘possible packing boxes’. A master packing box is generally a prepacked box that is shipped alone. For example you may sell shampoo in boxes of 6, 15, 30. If someone buys 8 of the item then it would pack in a 6 master box then the 2 would go in a combined box with other items.
By default the master box attribute (shipperhq_master_boxes) is not assigned to your Magento/Zoey attribute sets. You must add this to the attribute sets you need (under the Dimensional Shipping Group).
If you do not see this attribute please contact us for an extension update.
Setting up Master Boxes in ShipperHQ
In ShipperHQ you would set up a master box the same as any other box definition. The important criteria is that you must set a maximum quantity on the box. If you do not set a maximum qty it will be ignored from a master box packing perspective.
Once you have set up your boxes then synchronise these to your Magento installation.
Product Setup in Magento
In your Magento admin under the Dimensional tab you should see a multi-select for Possible Boxes and Master Boxes.
How it works
The algorithm in ShipperHQ will first try to pack all your items into the master box for each SKU. Once this is done it then looks at possible boxes and tries to pack the rest of the items into the smallest box that fits the most combined items based on your selection.
So looking at the example in the screenshot if you had 6 items it would pack 4 into the Master Box 4qty then the other 2 items would go in the 30x30x30 box.
Note: This feature is currently only available on Magento and Zoey.