Yes, you're right ghostrider, up thru the sticky side and FYI, I've done it with the thumbtack before and believe it or not, it works!! The biggest difference between this "homemade" tool and the $40-$80 ones is you have to fiddle with it more and measure from the needle etc to get an EXACT size on our circle. If you don't need it EXACT, then the tack works great.