You’ll need: 3D model of the hole that you want to make putt in, plastic ball, paper towel, and sandpaper (the plastic ball is essential) Place your model in the hole.
Make sure it is perfectly flat, and that there is not any bump in the shape of the holes.
Place your paper towel or plastic ball on top of the model, making sure it does not come in contact with the hole and the ball.
Once your model is firmly lodged in the plastic ball or paper towel (or both) cover it with a towel, so that the plastic can soak in the water, and allow it to dry.
Remove your model and place it in a dry area.
When you are ready to putt it, start with a shallow putt and then work your way up.
This process takes a little practice, but once you get it down, it is really quite easy.
Putt to see if the hole is closed!