Shopify's Order Printer app is free and easy to set up. Quickly print custom packing slips, invoices, labels, or receipts for all your orders. Print documents in bulk or one at a time depending on your needs.
To make customizations to templates, you’ll need experience with HTML and Liquid. If you don’t have experience with HTML or Liquid, Shopify Design Gurus can assist with minor customizations. Major customizations will need to be done by a third-party app, designer, or developer.