Double Rock Foam Hole Cutter Tufting is so easy when you have the right circle foam cutter. Using this tool with our Ottoman project plans will greatly reduce your time and will give you a better looking finished project. Just attach the cutter to your drill and watch how effortlessly and smoothly the cutter goes through foam. The diameter of the hole cut in the foam does not have to be very big. Of course, if you would like to have a smaller button that sets deeper, you should used the largest foam cutting tool and a smaller button. These ratios are all a matter of preference. Your main objective is to pass the twine through a hole, and to set the button into a trench. The foam cutting tool can vary in diameter from 1/2? to 1 1/2?. The standard upholstery button is size 30. Using the size 30 button with the 1/2 or 1? cutter will give you a “standard” look, using the larger foam cutting tool will give you a more plush, indented finish.