Hello, mike.
I'll help you out and ensure your invoices are printed in the right color.
There are several things you can do to ensure that your printer prints the correct ink. First of all, check the printer's default settings are configured to print in black ink. Open the printer settings on your computer and verify that the color settings are set to black and white or grayscale. Also, ensure that you have the latest printer drivers installed on your computer.
Additionally, test printing a plain document or a different file from another program on your computer. This will help identify if the issue is specific to QuickBooks Online or if it's a general printing problem. If it prints black ink for other documents in other programs but not in QuickBooks, you can check this article for further troubleshooting steps you can use for common printing issues: Fix QuickBooks Online printing issues on browsers for Windows.
Furthermore, If you're using a customized invoice template, try switching to a default template provided by QuickBooks Online. This will help determine if the issue is specific to the template you're using.
Feel free to get back to this thread if you need further assistance or have other concerns about printing the invoice. I'm always here to help. Keep safe and enjoy your weekend!