Move oven rack to the middle and preheat to 400 degrees. Cut 2 pieces of parchment paper to fit a rimmed sheet pan.
Important: Remove any rings, watches or bracelets and roll up your sleeves to bare your forearms.
Place 1 ball of dough on the floured cloth and roll it into a rectangle about 12 by 18 inches. Melt 3 tablespoons butter and brush about 1 tablespoon of it over the dough; this will help it stretch.
Placing your hands under the center of the dough, palms down, slowly begin pulling the dough outward. Work gently, but confidently. The dough is amazingly pliable. You also can use your fingertips to lift and pull, especially as you move toward the edges. Let gravity help you. Move around the dough, maintaining the rectangle shape, until it's about 18 inches wide and 24 to 28 inches long. If the dough tears, pinch it back together.
The dough should be as even as possible in its thinness, and thin enough to read through. Really.
With a scissor, trim the "lip" of dough along the edge. Discard.