I just use regular cardboard boxes.
Of course, the area I was whacking was curved, so maybe that has something to do with it.
Yes I'm from the states. Wisconsin, to be specific.
Here's a link to some paper tape to get you familiar with it:
http://cgi.ebay.com/GUMMED-WATERCOL...tem&pt=LH_DefaultDomain_0&hash=item563dc48539
It's also known as "gummed paper tape". There also is a reinforced version, which has some kind of strong fiber on the inside, and people use this for packing a lot. I chose the non-reinforced version because it looks smoother. They have some pretty thin-width tape, but I like the wide stuff. They sell it at all the art stores around here.
Basically it's got the consistency of a stronger version of a brown paper bag, and on one side of the strip there is adhesive that you have to get wet. I usually stick my fingers in a small cup or bowl of water and spread the water on like that. You can use a sponge or brush if that makes you more comfortable. You don't want to dip it into water, though. But anyway, it dries pretty quickly. Just rub the non-adhesive side while you are applying it to ensure that it sticks 100% and you're good to go.
I should really make a tutorial video on how I do my cardboard-making...hmmmm....