You can manually apply a Shipping Preset to a single order or multiple orders on the Orders page.
To apply a Shipping Preset from the Orders page:
The Shipping Preset details will appear in the SHIPPING SERVICE and PACKAGE columns next to the order(s) you apply the Preset to.
You can also apply a Shipping Preset when creating and purchasing a shipping label on the Buy a Label page.
To apply a Shipping Preset when buying a label:
Select the Package Type drop-down menu under the Package and Weight settings.
Select a custom Shipping Preset under User Presets or a USPS Flat Rate Packaging preset.
Edit Your Shipping Preset
Once you have selected your Shipping Preset from the Package Type drop-down menu, you can edit any of the available fields before calculating rates.
Click Calculate Rates to get updated rate quotes for your shipment, then proceed with creating your label.
Learn more about creating a label in the PayPal Shipping Center.