Checking the printer setup is an excellent first step toward completing your task, @VaTT. I appreciate you doing so.

I've got some extra troubleshooting you can do to the QuickBooks printer configuration. So, you'll be able to print the invoice as soon as possible as an envelope.

Let's start by changing the default printer to see if that was the problem. Do the following:

1. From the Start button, type Control Panel. 
2. Select Printers and Faxes or Devices and Printers. 
3. Right-click on a working printer and choose Set as Default Printer. 
4. Open QuickBooks and open the Printer Setup window to verify changes.

If the problem persists, I suggest downloading the QuickBooks Tool Hub. This tool will help fix strange printing problems in QuickBooks. Follow the steps below:

1. Download and install the most recent version (1.6.0.3) of the QuickBooks Tool Hub.
2. Go to the Program Problems and select QuickBooks PDF & Print Repair Tool. 
3. Re-print the invoice as an envelope again. 

If the issue remains, please follow Solutions 2 to 3 outlined in this article: Fix PDF and Print problems with QuickBooks Desktop.

If you're still having trouble printing in QuickBooks, I recommend checking out the following articles for more information on possible solutions:

• Resolve printing issues
• Fix common problems when you use and customize templates

Please never hesitate to contact me again if you have any more difficulties printing in QuickBooks. I'm always here to help you more. Keep safe.