How do I adjust brightness with Brother MFC - 290c?

[xcvbnmm]

Hello, I am having trouble setting the brightness on my printer. I am trying to print a cover for my new album to sell on CD but it always comes out too bright. I have tried everything, there are no buttons on the printer for that, not even the printer properties or preferences. Please somebody tell me how to change the brightness.

 

[PhilFrisbie]

You must darken the original image using image software such as Photoshop or GIMP.