I need to print grayscale halftones from my colour Epson printer. I have converted the photos to grayscale by changing the mode in Photoshop but the Epson printer still prints with 4-colours. I would like to screen them into halftones for printing and ultimately photocopying. Is this possible on the Epson NX625? I am running OS X Lion version 10.7.2 on iMac 2.7 GHz Intel Core i5. I can't seem to resolve this with Epson support.