LABL allows you to create branded packing slips by adding a company logo. You can also choose your own custom messaging as well.
From the dashboard click on settings to go to the settings page
Click on "Packing Slips"
Add a logo, select printing sizing format and include a custom message. You can also select additional settings (Including prices, show order total lines, and include product images with order items)
You can preview changes and then once you are happy with the settings you can click "save"