I can see how hard you tried here, sflynn1972. 

I understand how you'd want to share some information about printing invoices in QuickBooks Online.

As mentioned by my colleague above, the option to directly print customer statements to fit for window envelopes is unavailable in QuickBooks Online. 

 With this, I recommend sending this request to our product Developers so they can consider adding this in future updates.

Here's how:

1. Go to the Gear icon and select Feedback under Profile.
2. Enter your product comments and suggestions, then click Next to submit.

Additionally, you can check out this link to learn how to email or print multiple invoices, sales receipts, and estimates now or later in QuickBooks Online: Email or print multiple sales forms in QuickBooks Online.

You can always get back to us if you need anything else about printed forms in QuickBooks Online. Stay safe.