You can use Shopify's Order Printer app to print custom invoices, labels, receipts, packing slips, and other documents. For example:
- John owns an apparel store. Every time he fulfills an order from his store, he uses the Order Printer app to print a packing slip to include in the package.
- Sameera owns a custom wood furniture store. Every time she gets an order for a custom piece of furniture, she uses the Order Printer app to print an invoice to send to the customer.
You can customize Order Printer templates by using HTML, CSS, and Liquid code. Shopify Support can assist with minor customizations, but larger customizations need to be done by an experienced third party designer.