[Scribus] pantone colors

[Christoph Schäfer]

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The article is obsolete for 1.3x versions of Scribus.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.

>
> 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.

>
> 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.

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.
>
> Best regards
> Gustavo

HTH,

Christoph