[Groff] "creep" and booklets

[Ted Harding]

Hi Folks,

I'd welcome views and contributions about the following.

It concerns making a "booklet" out of a PS document.

1. Background:
If you have (say) a 16-page PS document, you can run it
through the following pipelikne:

  cat doc.ps | psbook | psnup -2 > doclet.ps

and doclet.ps will have a series of 8 pages, each with 2
of the original pages as follows:

1:   1 & 16
2:   2 & 15
3:   3 & 14
4:   4 & 13
5:   5 & 12
6:   6 & 11
7:   7 & 10
8:   8 &  9

You can now print out pages 1, 3, 5, 7 on one side of 4 sheets,
turn these over, and then 2, 4, 6, 8 on the other side. You then
get 4 sheets with printing as follows:

1      16
----+----
2      15

3      14
----+----
4      13

5      12
----+----
6      11

7      10
----+----
8       9


You can then staple these at "+", fold carefully down the middle,
and you have a nice little booklet which you can read in the
usual way.

Now here's the point. Because of the thickness of the paper,
the middle pages (toward the bottom of the above pile) are
puched outwards. To tidy this up, you can take a guillotine
and slice of the protruding bits (of all except the first).

However, this then leaves the print closer to the outside
edges on the centre pages that it is on the outside pages,
prgressively creeping outwards. This is what's called "creep"
and it can become quite noticeable.

So you then need to correct this, which can be done (and quite
easily in groff) by making small adjustments to the page offset
as you go from page to page (the details depend on what macro
package you use, but essentially require something to be done
in the macro which initiates a new page).

This requires offset changes, relative to normal printing,
as follows:


  0 1      16  0
    ----+----
  0 2      15  0
    
 -1 3      14 +1
    ----+----
 +1 4      13 -1
    
 -2 5      12 +2
    ----+----
 +2 6      11 -2
    
 -3 7      10 +3
    ----+----
 +3 8       9 -3


where (e.g.) "-2" means that the print on that (original) page
is to be shifted 2 creep-units to the left, and "+2" means 2
units to the right, relative to normal printing.

A fairly straightforward algorithm: odd pages left, even pages
right, by amounts increasing up to halfway, and then decreasing.
Note that 'psbook' will add extra blank pages so as to bring
the total up to a multiple of 4 (e.g. if the original had only
13 pages).

There are two things you need to know to determine exactly
how to do this. One is the total number of pages you will be
getting (which can be found from a dummy pass), so that you
can tell the algorithm where halfway is.

The other, of course, is the size of the "creep unit", and
this can only be found empirically. Print, staple, and slice;
then measure the change in width from outside to middle,
and divide by the number of sheets.


2. Groff implementation.
As I said, it's not difficult to arrange this in groff, by
suitably modifying your top-of-page macro.

a) First question. I think it's probably difficult, if not
   impossible, to write a "universal macro" which would work
   with any of the usual macro sets ("ms", "me", etc).
   Comments?

b) This wheel has undoubtedly been invented already.
   Anyone out there got good implementations?

c) I'm refining a macro for "ms" at the moment. Interested?


3. Practicalities.
These concern how you actually manipulate the paper, etc.
It's my experience that unless you're very careful, it's
difficult to get good and consistent results. Where things
can go slightly wrong are in putting the staples exactly in 
he middle, in folding, and in slicing off the protruding
bits.

Adequate results are quite easy though.

Any suggestions about procedure, from people who've been
along this road before? This could include recommendations
about the use of equipment to properly hold the pages when
being stapled and folded, to ensure a good clean fold, etc.
Preferably suitable for implementation on the kitchen table.

Then there are ths issues that arise with larger documents,
where you eed to make them up of "signatures" each with few
sheets. With standard 80gm/m2 printer paper, I've found that
16-sheet signatures are about as far as one wants to go.

I've found that good-quality thinner paper is hard to come by.

Having got your signatures, they then need to be attached
together. For this, it's not ideal if each signature was
stapled. Any recommendations for (a) making the central
attachment for a signature instead of stapling; (b) binding
signatures together?


With thanks, and best wishes to all,
Ted.


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E-Mail: (Ted Harding) <address@hidden>
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Date: 04-Nov-05                                       Time: 00:01:08
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