I struggled with exactly this model and use case. Check out the AUR package for the 2270DW, and make sure image quality is set to 600dpi. That was the magic com

I struggled with exactly this model and use case. Check out the AUR package for the 2270DW, and make sure image quality is set to 600dpi. That was the magic combination for me. Also check out the Arch wiki on Brother printers.