By default, multi-channel fulfillment (MCF) orders come in Amazon-branded boxes. So if you ship your Shopify orders via FBA, then the customers will receive Amazon-branded boxes.
Amazon has now added an option to use non-Amazon branded packaging for fulfilling multichannel orders via the 'MCF blank box order fulfillment' Program.
Simply select 'Yes' for Blank Box in the Shipr dashboard. The app will then configure Amazon to fulfill your Shopify orders in a completely unbranded package (no Amazon tape or logo, nothing).
Note:
This is currently in beta on Amazon’s side. Not all merchants have access to this program. If Blank Box is not activated for your account, then the app will ship the orders with normal Amazon-branded boxes.