There are few different types of labels that Amazon provides for sellers. Please see information about each below:

Amazon Customer Orders - These are orders to fulfill customer orders. You may simply leave the layout as "default" and this will produce a label in 4x6 size in the proper format for Phomemo and other thermal printers.



Amazon ASIN product labels - These are the labels to place on products before sending to Amazon. You may also send these directly to Phomemo from Amazon's Scan & ship page: Printing FBA Product ASIN labels.

Amazon FBA Labels for outside the box - These are the labels that are placed outside of the box containing   your product that is being sent to Amazon's warehouse.

The Phomemo team has put together a free service that can crop multiple pages into a 4x6 format. Visit:  https://phomemo.com/pages/label-transformer