Page 164 - Graphic Design and Print Production Fundamentals

152 Chapter 5. Pre-press
impose the images so the shapes nest inside each other. This is usually outside of the automatic features
for imposition in a RIP, and requires operator intervention. In that case, the imposition operator must
know the die cutting or router processes very well to make sure the imaged media can be cut out even
though it is nested with another image.

This nesting of images to be die cut after imaging is most prevalent in flexographic printing for
packaging. Most package or label shapes are not square and the media is expensive. The imposition
function becomes very important for preparing flexographic plates. Nesting the die cut shapes for several
packages together on a continuous roll of media takes very specialized software and a highly skilled
operator. There are many variables to consider, including media thickness, ink coverage, die shapes,
glue releases, and image floor on the flexo plate. Flexo imaging for packaging generally takes more
understanding of CAD software and the construction of the final three-dimensional product. Imposition
operators must know the structural requirements as well as the press limitations to nest together several
package images on the same press run.

The final consideration for all impositions in all imaging technologies is the computer resource
requirements for the RIP. We usually require an imaging engine to raster a single document, and proof
it one page at a time through a proofing device. When we impose the same document with many other
pages in completely different orientations, sometimes RIP processing errors can occur. Fonts drop out,
and more commonly, transparent elements do not process properly. This is another checkpoint to make
sure the imposed image matches the proof of the single page. It is essential to discuss preflighting for
print at this point to establish where the routine checkpoints in document processing should be.

Media Attributions

• work and turn 01 by Ken Jeffrey

• work and turn 02 by Ken Jeffrey
• work and tumble by Ken Jeffrey

• cut and stack-03 by Ken Jeffrey