[Zope] Manipulating images in Zope/Python

I am looking for strategy to programmatically create a customized printable certificate of completion for our Learning Delivery System courses (the system is Zope/Python based). My current plan is to use the Python Imaging Library to create the image (probably by overlaying some text on a stock image of a completion certificate to create a new image). The final image will then be emailed as an attachment to users. Is this a reasonable approach? Any others that anybody can suggest? Any samples of doing anything like this that anyone can point to?