Bluetooth printing from app

I am in the process of writing an app to do some printing offline. The app will be running on iPad's and that will not have access to wifi. We are looking at using Bluetooth printers to accomplish this but not sure Airprint will work on the printer. The printing is not receipt type printing but full 8.5 X 11 printing. Has anyone done this? If so, what printer and device did you use? Have you had any issues?

I am wondering if the best course of action, it to purchase a pocket router that can be attached to the printer and creates a private network the ipad could connect to and print from when plugged in.