Our wind slit cutter allows you to easily cut half-circles (or even full circles) ranging from just under 3" to a full 12" in diameter into your custom vinyl banners. As for using it - set the size you need by twisting the base of the knob and using the underside (it's a ruler marked in centimeters) to select the radius from the center where you'll place the knob. Once done, twist the dial on the blade handle and slide it down until the tip of the cutter shows. You're ready to cut some wind slits now.
Lay your banner on a flat surface that you don't mind scratching, upside down and with the bottom of the banner farthest from you. This is so that, if the knob is set too low or you don't keep it in one place, the dimple and/or scratch is done to the non-graphics side. As for standing at the "top" of the banner, you'll see. Select your first cut, 6-8" away from the edge, push down on the knob, and firmly rotate the blade handle up and away from yourself (towards the bottom of the banner) in a clockwise arc. This makes it so you're not trying to cross one hand under the other (if pulling the tool towards yourself) and by positioning yourself at the top of your custom banner, the wind slits will hang down, or 'be closed' when the wind isn't passing through them.
A great tool to have for anyone using large outdoor banners or for anyone selling vinyl banners to customers. The four star rating doesn't reflect a flaw in the tool, but the risk of damaging a custom sign if used improperly. Practice, as they say, makes perfect, and with the right amount of it, this will make perfect, half-moon wind vents time and again. And with the Snap-Off Blade, both the practice and the wind slit won't be slowed by any dull blades.