You won’t need anything special. Just a couple of shopping sacks, a ruler, marker pen and a pair of scissors.
First, find a couple of the large brown paper sacks of the kind that you bring groceries home from the store with. Two of the same sized bags work best. (In this case, it will be paper, not plastic)
Carefully undo the flaps that are folded and glued that make up the bottom of the sacks. If you tear them a little bit, no big deal. Do this on both bags.
Now cut each sack up the side so that you end up with one big rectangle of paper.
Position the edges that were the tops of the bags together and tape them. Now you will have one big almost square piece that is about 37 inches by 42 inches. This will let you make a circle 36 inches in diameter. If you need a larger circle, just add more paper on the edges to make a bigger square. It should look like this picture.