[Scribus] pantone colors

[Gustavo Homem]

Hi Christoph,

On Friday 05 May 2006 01:01, Christoph Sch?fer wrote:
> Hi Gustavo,
>
> Am Freitag, 5. Mai 2006 01:27 schrieb Gustavo Homem:
> > Hello,
> >
> > I was asked about pantone color support on Scribus and I found this on
> > the wiki:
> >
> > http://wiki.scribus.net/index.php/Scribus_and_Pantone_colors
>
> The article is obsolete for 1.3x versions of Scribus.
>
> > If I understood the comments correctly  we should be able to produce a
> > PDF with Pantone colors by:
> >
> > - defining a color in the color editor and marking it as a spot color
> > - naming this color as "Pantone 185 C" or any other Pantone name
> > - not checking the "Convert spot colors to process colors" on the PDF
> > export dialog
> >
> > Do these steps actually generate a PDF with Pantone colors? Spot colors
> > are rendered based on their names, right?
>
> Spot colours aren't "generated" in a PDF, only the inforomation for the
> printer that colour "xyz" is a spot colour called "Pantone blah". The
> printer then knows that he has to use an extra plate to print this colour.
>

What you mean by printer in this context ? Is it the guy behind the desk at 
the print shop? Or the machine that prints?

Anyway, the question is: 

do the above steps enable me to produce a PDF which contains the right 
indications for a "print shop" to produce Pantone colors for me?

(even if I had to look them up on a book, and the representation manually I 
picked for them on the screen is not very faithful)

Can I hand over such PDF and expect them to understand it, with no further 
questions asked?

> > If so, the missing bit is an algorithm to display them "correctly" on
> > screen, right?
>
> No ink colour can be displayed "correctly" on screen. It is possible to
> come cery close, but accuracy is almost impossible.
>

I am aware of that, that's why I used the "". I suppose "very close" is what 
programs that claim Pantone support do...


> > On the link above a set of "Pantone" colours to include on scribus.rc is
> > mentioned, but it is not available anymore. Does someone have this?
>
> It probably violated copyrights, and I don't think we should support this.
>
> > Actually I tried doing that, by creating two colors which were marked as
> > spot colors on Scribus. One was called "Pantone 185 C" and the other
> > "Foobar xpto".
> >
> > Then I generated a PDF. I expected Acrobat to only render the former,
> > since there is no spot color named "Foobar xpto", but it showed both.
>
> You defined a colour with either CMYK or RGB values. That's independent of
> spot colours. 
> > The name of the colour and your labeling as a spot colour  
> will indicate the required colour to the printer.
>

Can you explain the difference between a spot colour and a non-spot color in 
terms of what is stored on the PDF?

> The only way to handle spot colours effectively is to buy a colour book.
> colour books generally contain all informations needed for output: Name,
> RGB, CMYK values, HTML codes etc. You have to choose a colour from that
> printed book, type in the values (for printing usually CMYK) and the name.
> When you export to PDF or Postscript you can decide if you want to override
> the spot colour option and let the colour be composed by process colours
> instead.
>
> > So, how can I know when the PDF really contains Pantone colors?
>
> It doesn't. See above.
>

It must somehow, or else marking it as "spot color" would have no effect. I 
don't mean "containing the colors", the question is more:

How do I know if this foobar.pdf contains the bits which mark my spot colors 
as spot colors with the correct names assigned?

Sorry for not understanding at first :-)

Best regards
Gustavo

> > Best regards
> > Gustavo
>
> HTH,
>
> Christoph

-- 
Angulo S?lido - Tecnologias de Informa??o
http://angulosolido.pt