[scribus] PDF Colour separations

[Gregory Pittman]

On 05/22/2012 10:18 PM, Gregory Pittman wrote:
> On 05/22/2012 08:56 PM, Frank Cox wrote:
>> To this point, I have been creating plates by printing to a 
>> colour-separated ps
>> file, then doing an imposition from that into four pdf files (one for 
>> each
>> colour) then printing each pdf file to the appropriate series of plates.
>> Unfortunately, ghostscript blows up once in a while using that output 
>> due to, I
>> think, poor quality fonts being used in the original document.
>> (10,000 Fonts for $1.49!)  Unfortunately, I can't persuade the folks 
>> who create
>> this thing to stick to using good quality fonts (I've tried several 
>> times) so
>> I'm stuck with the consequences.
>>
>> I am now considering the idea of starting from a pdf file instead of 
>> a ps file
>> (not knowing if the output will be any different or better or not) 
>> but have
>> discovered that there is no obvious way to create a colour separated 
>> pdf file
>> in Scribus.  Export to PDF has several options, none of which appear 
>> to do what
>> I can do by printing to a ps file.
>>
>> So my question is, how can I get a set of colour separated pdf files 
>> out of a
>> Scribus-generated PDF file?  I see that ghostscript now supports a 
>> tiffsep
>> device, but that will give me a series of tiffs.  Should I go with 
>> that and use
>> tiff2pdf to create my pdf files for the plates?  Or is there a better 
>> way?
>>
>> Or am I wasting my effort here and won't gain anything different by 
>> starting my
>> imposition and colour separation from a PDF instead of a ps file?
>>
> Something I tried and can't really say I succeeded at was printing 
> separations to a PS file, then importing this to Scribus as a vector 
> file.
> I just created a very simple document with a single photograph.
> The hitch I got into was that there seems to be something wrong with 
> the importation of the PS files, since they're clipped -- i.e., the 
> entire image did not show. Something of a workaround was to ungroup 
> the PS, which gives you 2 overlapping boundary boxes, and they seemed 
> a bit out of line, which was apparently the source of clipping. One 
> ungrouped box was labeled Image2 and the other Group1. If I enlarged 
> Group1 I could then see all the image. (Incidentally, if you then try 
> to ungroup the box labeled Group1, Scribus crashes with Signal 11*) If 
> you fiddle with the Image2 box you may mess up the proportions.
>
> That file could then be exported as a color separated PDF. The trick 
> would be coming up with a method to make sure the separations are 
> lined up properly on the various separated PDFs.
>
Some further experiment suggests it's not workable. I tried this again, 
this time with one image frame, and one text frame.
What I found was that by using layers one can import the PS separation 
to its own layer. Next ungroup. Now delete the box which is still 
labeled Group1 (or whatever number) by selecting it alone. Now all the 
image shows and the rest of the content (color permitting), and one can 
align with the original content which you can show/hide on its own layer.
The problem is that even though the proportions of the image and of text 
(converted to outlines) was correct, their relative positions were not, 
so selecting them all and repositioning won't work, you would have to 
reposition each element, then of course do this for each separation...!

So apparently something goes wrong with importation of PS into Scribus. 
I would add  that, for example, loading the PS file with okular shows 
everything appearing and positioned correctly.

This does bring up an option you might try. Use okular and File > Import 
PostScript as PDF, which converts the PS to PDF, then save. See if that 
might work -- it seemed to load into Adobe Reader without problems.

Greg