Re: crop marks in PDF for printing

[Alexander Kobel]

Hi Hraban, hi all.

On 2016-11-06 18:10, Henning Hraban Ramm wrote:
> Am 2016-11-04 um 13:44 schrieb Alexander Kobel <address@hidden>:
>
> > On 2016-11-04 11:56, Henning Hraban Ramm wrote:
> > > (BTW I studied typesetter and printing engineer, worked in printshops for 
> > > decades.)
> >
> > That reminds me to ask a professional a question that I was pondering about 
> > several times earlier on.
>
> ;) I know someone of your exact name who runs a copyshop...

Interesting. Given that I never met anyone sharing my last name outside 
of my family, I'm quite surprised...

> > In many brochure-bound volumes of more than two or three sheets (say, 60+ 
> > pages), the paper is cut to align flush when the brochure is closed.  So the 
> > inner sheets are (sometimes significantly, say in the order of 5mm per page or 
> > 10mm per sheet) narrower than the outer ones.  Does / should this impact the 
> > layout of the page?  And if so, how?
>
> It should affect the layout insofar as the page contents (should) get moved a 
> few millimeters.
> That’s a task for the imposition software at the printshop, or previously for the 
> "Druckvorlagenhersteller" (lithographer?).

Should the contents be moved towards the binding or towards the outer edge?

> > In particular, should the line lengths be varied throughout the book such that 
> > the margins remain identical, or should the inner margin be changed, or the 
> > outer one?  IIUC, traditional (text) layout rules are meant to compensate for 
> > the visually smaller inner margins when the book is opened, so they say to 
> > /increase/ inner margins. On the other hand, many classical layout rules are 
> > based on the fact that the outer margin should be as wide as twice the inner 
> > margin (hence, whitespace appear identical).  But if the inner sheets are 
> > smaller, but the binding offset /increases/ inner margins, the outer margins 
> > get even more compressed?
> >
> > For music, we have more freedom in layout; the needs are totally different from 
> > the ones for text, and things like character count per line do not apply.  As 
> > far as I'm concerned, the most important consideration for sheet music page 
> > layout is proper places for page turns, and as little of them as possible - 
> > without sacrificing readability.  Margins or their symmetry seem to be much 
> > less important than for text.
> > Still, for aesthetical reasons, I could imagine that either ratio between 
> > margins and line length, or the absolute margin widths, should be the same 
> > throughout the book.  Opinions and/or professional authority-based knowledge, 
> > anyone?
>
> Interesting approach – I never heard of anyone doing this, but it makes sense 
> and could even be applied to text layout.
>
> You or the typesetting system would need to know how the book will get bound and which pages to 
> change how – if it’s just one booklet (back stitched) or a properly bound, thicker volume that 
> consists of several "booklets" (thread bound), or if it’s "perfect bound" 
> (single pages glued). In the last case, you can avoid layout correction.

Yes, that's obviously the problem. Even if you already know the 
parameters, it sounds like a pretty difficult task for a layout system 
if the content area changes with the number of pages and vice versa. 
Long compile times ahead, and probably for little benefit... Similar to 
why Lilypond takes much longer if page breaks are determined on-the-fly, 
or why LaTeX compile times are much longer with microtype, I guess.

But at least I'm glad that an experienced typesetter agrees with my 
idea. :-)

> Usual layout correction affects only the margins.

Pure lazyness. ;-)


Cheers,
Alexander