Imposition is one of the fundamental steps in the prepress printing process. It consists in the arrangement of the printed product’s pages on the printer’s sheet, in order to obtain faster printing, simplified binding and less waste of paper.
Correct imposition minimizes printing time by maximizing the number of pages per impression, reducing cost of press time and materials. To achieve this, the printed sheet must be filled as fully as possible.
Imposition is affected by five different parameters:
Correct imposition minimizes printing time by maximizing the number of pages per impression, reducing cost of press time and materials. To achieve this, the printed sheet must be filled as fully as possible.
Imposition is affected by five different parameters:
- Format of the product: The size of the finished page determines how many pages can be printed on a single sheet.
- Number of pages of the printed product: The compositor must determine how many sheetsare to be printed to create a finished book.
- Stitching/binding method: The compositor must understand how the sheets are placed to form the signatures that compose the finished book.
- Paper fiber direction: Many papers have a "grain," reflecting the alignment of the paper fibers. That these fibers must run lengthwise along the fold influences the alignment, hence the position, of the pages on the printed sheet.
- Finishing and binding
To understand how the pages are related to each other, an imposition dummy may be used. This is made by folding several sheets of paper in the way the press will print and fold the product. A little copy is then created, and this can help paginate the product.