ice cream sandwich case for the iPhone 4/4S is handmade by iCaseSeraSera on Etsy; the image is printed on a thin sheet of aluminum using a special technique and adhered permanently to the back of the plastic case…which sounds like no easy task but at least the finished product will last more than a few bites.
If you’re not a fan of shopping on Etsy and supporting the handmade community (i.e., starving artists) you could also find a similar ice cream sandwich case for your iPhone on Amazon. I won’t judge. That’s totally up to you. No guilt trip here.