Hi Gustavo, > > > > 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?
The guy operating the RIP ;) > > 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? 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. > > > > 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. The developers will be able to explain the technical details better than I ;) > > > 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 :-) You need special software for this. AFAICT, none of them is available for Linux yet :( > > Best regards > Gustavo Cheers, Christoph
