A imposition is the overall layout of pages of a job as it will be printed.
An imposition is made up of signatures. Those are the individual sheets of
paper that are printed on. Each signature generally contain 8 (4 pages on
each side of the sheet), 16 page (more common) or 32 (if the press size is
big enough) pages. You can have 4 page signatures which would basically be
printer spreads. You can mix and match signatures in a imposition depending
on manufacturing needs. When producing magazines on a web press you may have
a four page signature that is the covers running on a heavy gloss stock, 70#
gloss lets say. Where as the body may be running on a 45# book using 32
pages signatures (two 16page signatures). They all end up folded and ready
for bindery at the back end of the press.
See how it gets a bit complicated? Don't do your printer any favors by
sending them an imposed file. There are job specific parameters that need to
be accounted for. There are also specific requirements for a specific press
that need to be taken into consideration. At the last minute it is not
uncommon for a printer to switch presses because of other production needs.
As for why a printer would ask for single page PostScript it is because if
you have a change to one page the printer can replace the one page. If you
were to supply a new multi-page document then the printer might have a lot
of fixes to re-apply. Where as replacing one new page is relatively simple.
It all depends on the printer and their specific workflow "habits". All of
the modern systems (even the older ones) will take a multi-page PostScript
or PDF.
Like Mike and I have said before, just ask your printer before you do
anything.
Matt Beals
Consultant
Enfocus Certified Trainer
Markzware Recognized Trainer
(206) 201-2320 - Main
(720) 367-3869 - eFax
mailto:
[email protected]
Come visit me at:
http://www.automatetheworkflow.com
http://www.mattbeals.com
http://blog.mattbeals.com
Friends don't let friends write HTML email