Now all I have to do is see if the check stock I got will work with the laser printer... One of the security features is that it has a little temperature-sensitive area of printing: if you hold your thumb on it for a moment, a little printed image of a fingerprint goes away, then comes back. Unfortunately, running it through the laser printer makes the image go away, and it doesn't seem to want to return. I stuck some printed checks in the refrigerator just to see if that would resurrect the printing. (How's that for a weird place to put checks?)
The finished checks have the same Animaniacs images I've been using, except that I had to shrink them a bit because the HP DeskJet 5550 has a minimum right margin of .25 inch, as opposed to the .125 inch of the Epson I'd been using. Argh. I made it an even border all around, but it's still mildly aggravating.