Scoring and Perforating
- A score is a crease or cut in a sheet of paper to create a crisp fold and minimize cracking.
- Scoring is done from the side of the paper opposite the fold. If the piece folds in several directions scoring will have to be done from both sides of the sheet.
- There are a number of ways to score, but the two most common methods are die scoring and rotary scoring.
- Die scoring is done on a letterpress using a scoring rule. This process give the best quality and multiple scores in different lengths and directions can be done on one pass through the press.
- Rotary scoring is done on a special machine using one or more scoring wheels. Multiple scores can be done in one pass but they must be in the same direction and across the entire sheet. This method is commonly used to create the spines and hinges on perfect-bound books. Die scoring is recommended over rotary scoring for stocks heavier than 12-point or where cracking is a problem.
- Scoring with the paper grain rather than against it gives the smoothest fold. Scoring against the grain may result in cracking but often provides a stronger fold.
- Scoring and perforating can be done at the same time.
- Rotary scoring is usually quicker and less expensive than die scoring.
- A perforation is a series of small holes or slits in a sheet of paper to facilitate tearing at a fixed point.
- Perforations, like scoring, can be either done on a letterpress or a rotary machine.
- Die perforations can be any number, length and direction on the sheet in one pass through the press.
- Rotary perforations must run in one direction for each pass through the machine and must run the entire width or length of the sheet.
- Perforations can be very coarse down to extremely fine "micro perfs".