If the vertical scoring option is shown on the option menu for your order, your project is most likely being produced on a medium to heavy card stock which may or may not require the piece to be produced flat with a score for folding manually later. Our greeting cards for instance come with a score included in the price. Scoring a card stock helps to preserve the integrity and straightness of the manual fold and allows the card stock to more easily lie flat when closed. As an example, if you were to attempt to fold a piece of card board in half and you tried to do it without scoring it first (say using your finger nail or a screw driver, the odds of it folding exactly in half in a clean, straight line would be low).