[Scribus] pantone colors

[Gustavo Homem]

Hi Christoph,

On Friday 05 May 2006 02:01, Christoph Sch?fer wrote:
> Hi Gustavo,
>
> Am Freitag, 5. Mai 2006 02:45 schrieb Gustavo Homem:
> > Hi Christoph,
> >
> > [...]
> >
> > > > 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?
> > >
> > > Yes.
> > >
> > > > (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?
> > >
> > > "With no further questions asked" is always a bad idea. Success in
> > > printing has a lot do with communication between human beings, since
> > > there are hundreds of uncertainties. It's almost the same as asking a
> > > doctor for help by describing shortly what you think is wrong with you.
> >
> > seems that I picked the wrong words there.... what I want to know, is if
> > such a PDF can be automatically interpreted by their workflow, if the
> > colors have correct Pantone names and are marked as spot colors.
>
> Yes, it can.

Good!

>
> > > > > > 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...
> > >
> > > They don't even do that. Read the disclaimers!
> > >
> > > > Can you explain the difference between a spot colour and a non-spot
> > > > color in terms of what is stored on the PDF?
> > >
> > > A spot colour is stored as a separate colour (only the name of the
> > > colour) in the PDF file, whereas a process colour is stored in CMYK/RGB
> > > values.
> >
> > aha! Then why is it that when I marked as color as spot and gave it a
> > foobar name Acrobat still rendered it?  If only the name was there, it
> > shouldn't , I think.
>
> Because in reality, you defined a RGB/CMYK colour and only marked it as a
> spot colour, which is totally independent from the values you entered. You
> can define a blue colour, choose a red one from a colour book, enter the
> name, define it as a spot colour, and the printer will use use red, while
> you see blue on your screen or on a print from your inkjet.
>

Ah... so both things are stored on the PDF: RGB/CMYK and the spot bit + colour 
name !

> > > The
> > > developers will be able to explain the technical details better than I
> > > ;)
> > >
> > > > Sorry for not understanding at first :-)
> > >
> > > You need special software for this. AFAICT, none of them is available
> > > for Linux yet :(
> >
> > but this list does a god job anyway.
>
> That's what it's for :)

This discussion was very helpful, thanks a lot.

I think most things are now clear, regarding what I wanted to understand.

Best regards
Gustavo


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