Cheap and Easy Tube Document Carrier

I am studying design at uni and am often surprised that I am not often surprised by the ingenuity of fellow students. It seems that it is too easy to run off to a shop and buy something when creative thinking can easily solve a problem. This cheap solution to the problem of easily carrying rolled, poster sized work was seen in a recent lab session. I have no idea who it belonged to so credits cannot be given. To buy the plastic tube version you are looking at  spending $15 - $20. To make the cardboard one you are looking at a great way to recycle an old mailing tube, two rubber armbands and an old bag strap. You can now take that $15 - $20 and buy some better food than instant noodles. Less landfill and more money for food. The only loser here is the art supplies shop.