I watched the inventor of this demo it. First, it is essential to pound the pounce on a solid surface very hard at least 50 times at first time using it. This is to get the marking surface overfilled with chalk, so it flows freely over the stencils. It then works in one swipe over the stencil. It lasts a long time when properly saturated. I like the iron away chalk. I suggest you tape the pounce closed. I dropped mine and it popped open. What a mess.