I wanted to make a shirt with the Aperture logo on it so thats what i did, I even put a companion cube with wings on it. I can commission them for about 15 bucks. About 5 for the Shirt and then 10 for anything else i would need to get and to ship it. It only cost me like 10 bucks all together to make. About 8 bucks for the tank top and then 2 for the fabric paint.
Portal belongs to valve.
If you want one just PM me what you would want designed on it and ill see what I can do.