sorry for the late reply, i would use a 110lbs card stock paper, it's good for any household printer and can hold allot of structure, however with something this big you would also need to make braces (or ribs) on the inside to help hold its shape, also fiberglass resin it in the end and it will be tough as can be...if you cant use resin, i would at least give it allot of coats in woodglue to try and harden it