To cut out the imprint on the laser, I'm rastoring the image at 600 DPI. First, I creat the image in CorelDraw. I should also add that there is an actual "stamp program" on the computer that I wasn't aware of before, so If I learn it I'll update this Instructable as necessary. I'm using the standard business card size: 2" tall x 3.5" wide. In order to get the laser to rastor everything but the lettering so that it is raised, as opposed to simply engraving the lettering into the rubber, I background fill the card black and make the lettering white. Then, flip the image horizontally, so that your writing is backwards. This is to ensure that it will read the right way when you press it into your paper.
You can see the rastor and vector settings (vector just to cut out the card blank after engraving), as well as some pictures of the Epilog Helix in action. I actually did three passes in all to increase the depth of the surrounding rubber in relation to the pad and avoid accidental imprints.