How do I print packing slips? The answer I find is
4. If you're not using Shopify Shipping, then click Mark as fulfilled
5. Click Print packing slip.
6. Click Print.
but there is no option to print packing slip without going into each order.
Also I want to print before fulfilling.
I would also like to understand how to programmatically create pack slips for multiple orders to be sent to a 3rd party vendor who will be fulfilling those from a different warehouse then the majority of our products.
You can print the order packing slip as you said, just add in another step:
5. Click Print packing slip at the top.
7. Return to order without clicking on Fulfill Items.