Scoring is a great option to create a crisp clean fold for your heavier weight stocks. Stocks for invitations, thank you cards, booklet covers and brochures will benefit from scoring the fold lines.
When thicker paper is folded without scoring, it cracks along the spine. Because the paper cracks, so does the ink that is printed on it. This is especially noticeable when there is a darker ink that shows the white paper through the cracked area. Scoring is an excellent option to keep your projects looking beautiful to the end.