Under Output>Print select Page Setup
Change "Scale Mode" to Scaled Print, then chose 1.00 as your scale.
Make sure the Printer Paper is selected as the size you need.
Under Color Set, choose "Mono" (to give you solid black for the transfer.)
On the same dialog, click "Advanced", here you setup what layer you want to print, and you may want to choose Mirror if the image is being flipped onto the board.
Hit Ok to all that, and then Print>>Print Preview and if anything isn't right, go back and sort it out in those dialogs previous.