How do I sort items on an invoice

alltrightbricks

I have recently started including an invoice with my orders, but I've noticed that I can open the order, and sort by category etc for pulling the order, but when I click "invoice" it messes up the pattern, and I cannot figure out how to sort the invoice. I would prefer to sort the invoice by color as I think that will be the easiest for the buyer to verify by, but can't figure a way to do it. I cannot seem to get anything but random for the invoice.
Verifying a large lot order this way is going to be a huge pain. ----Is there something I'm missing here?
Thanks for the help.
Katie