Review (2/5): and it's a great idea, but it really just doesn't work
They kind of do what they're supposed to do, and it's a great idea, but it really just doesn't work. You find a stencil that fits as best as you can get it and try to frame your fingernail in the little opening without them falling off your fingers or totally tearing your fingernail off your hand from the root or from the side or cutting off the circulation in your fingertips. Tried them once, they were supremely uncomfortable and didn't produce good results- I still got nail polish all over my fingertips that somehow seeped under the poorly-fitted cracks, and of course once you paint your fingernails with them on, you've got to sit there with them on until it dries. I ended up throwing them out.