I want to customize the inside of an iPhone case?

I'm looking to customize the inside of an iPhone 4 case. However, i'm having a hard time finding someone who will do it. I want a completely normal back, with a special message either engraved or printed on the inside. Any ideas on where to do this/ any alternatives to this option?

I think office max has printers you can pay to use.

I think you can go to an engraver's store and have someone laser burn one onto the inside. I have seen some laser engraving and they look amazing!