Mia's tank is just so boring and bleh that I want to decorate it more, I'm looking for 36 x 18 wallpaper/background to put in the back, but I can't seem to find any :/
You can edit the photo to be a certain size and give them a digital copy. They can print on poster sized paper so it fits the size of the photo. It looks distorted if it's not a reasonably high res photo though. There are some online companies that might be able to do it and ship it as well but I haven't done that aside from small prints from Snapfish etc.