I've visited the official website and it's clearly specified on the website that the software doesn't print checks, but rather it fills your pre-printed checks.
Here is what the developer of the application saying about it:
This software does not print your actual check, it fills in your pre-printed check form. - http://www.starresoft.com/checkwriter.htm
To find more about it, use the link below to access the page and read its entire description. You can get in touch with the developers as well: http://www.starresoft.com/contact.htm