See also Make a magnetic throwing circle
In olden days, players drew their circles in the dirt using a toe, a finger, or a stick. Some liked to carry a special circle-drawing tool. Plastic circles were introduced about 2005 and quickly became popular. Today, you can buy plastic circles online from Petanque America or Decathlon. They work well, but some of them are more expensive than they should be, and because of their bulky shape they can be expensive to ship. That’s why players often choose to to make their own.
FIPJP rules specify that the inside diameter of a plastic throwing circle should be 50 centimeters. The circumference of such a circle is 157 centimeters, which is equal to 62″ or 5’2″.
I went down to my local hardware store and bought 6 feet of plastic tubing. I cut off a long section (62″), and also a short section about 2 inches long. I split the short section in half lengthwise, and then made a splint by using a pair of pliers to fold one of the halves lengthwise. Using the pliers, I jammed the splint into the open ends of the long sections. Once it was installed, the splint held the ends together so that the tubing formed a closed circle. Finally, I put a small square of duct tape over the joint to help keep the ends together if the circle was roughly handled. Voila, une rond.
Unfortunately, the first kind of tubing that I bought had been coiled into small tight loops at the hardware store. The tubing always wanted to return to those tight little loops and my circle refused to be truly circular.
So I went back to the hardware store and found a smaller size of polyethylene (PE) tubing (5/16″ outer diameter, 3/16″ inner diameter) that had been coiled into larger, looser loops. (The cost was about $3.00.) When I made a throwing circle from it, the cirlce kept its proper circular shape. The final product works well.