Planning for Imposition

Commercial printers often use large sheets of paper that they fold, cut, and trim to the finished size. One of many possible ways of printing multiple pages is shown in the illustration on this page (or here. This example is a 16-page "sheetwise imposition" signature. One large sheet is printed with 8 pages on each side. The solid lines are for cutting. The dashed lines are where the paper is folded. Once cut and folded the pages form a 16 page booklet or signature. Several such signatures may be assembled into the final book or other publication.

Plan for color and graphics with imposition knowledge
Knowing how commercial printers position your pages for printing can be an important planning factor when it comes to adding color and spreading graphics across a 2-page spread.

As with any job, consult your printer early in the planning process to insure good results and to make sure that your job doesn't involve processes that your printer cannot handle.

• Reduce the cost of adding a third color to a job
  Run black with blue on one side of the press sheet. Then run black with green on the other side. You may incur a slight extra charge for the color change but not as much as if you were mixing black, blue, and green all on one sheet and having to run each side through the press multiple times.

• Reduce the cost of four-color process printing
  If planning a publication that mixes black and white with some four-color process illustrations -- plan all color so that it falls on one side of a press sheet or all within a single signature when the job consists of multiple signatures.

• Print better color from your desktop
  Even for desktop printing, understanding imposition is important. Most inkjet papers are designed to produce best results on only one side. Need double sided documents? Plan your color for one side and black and white only for the second side.

• Insure smooth page-to-page transition of photos and graphics
  When an image crosses the gutter (spreads across 2 pages) it may not align properly in the final assembled document. Plan graphics that cross the gutter for pages with a natural spread — i.e. no worry with exactly matching cut edges. For example, in our 16-page signature described above, a graphic crossing pages 10-11 would have a cut down the middle. Whereas, a graphic spread across pages 8-9 would have a fold, not a cut — less worry with proper alignment.

Next, visualize imposition with mock-ups and charts.