Peel the potatoes, and place in bowl of cold water to prevent browning. Place potatoes into a large wooden or metal spoon. Using a sharp knife, make slices across the potato the short way about 1/8 to 1/4 inch apart, making sure to cut down to the lip of the spoon, not all the way through the potato. The slices should stay connected at the bottom, and the spoon helps keep the depth even. Return the potato to the bowl of water, and proceed with the remaining potatoes.