How to use Pantone colours with Scribus: Difference between revisions

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{{HOWTO Index}}
#redirect [[How to use spot colours with Scribus]]
 
 
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'''IMPORTANT NOTE:'''
This article is still work in progress, the intended target audience are '''DTP beginners'''. Therefore, please keep it simple.
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==Spot colours==
 
Spot colours are single ink colours, rather than colours produced by four (CMYK) or six (CMYKOG) inks in the printing process (process colours). They can be obtained by special vendors, but sometimes the printers have found their own way of mixing inks to match defined colours.
 
Spot colours may be desired for two reasons:
 
* Economy: if the document to print contains less than four colours, it may be less expensive to use ready mixed inks than to render them as a mixture of inks. This is because less plates are required.
 
* quality: it isn't allways possible equal a certain colour with a mixture of inks
 
More on spot colours can be found [http://en.wikipedia.org/wiki/Spot_color here].
 
The PDF specification supports the concept of spot colours. In terms of PDF information, a spot colour is merely a colour reference which is defined by a name. This name is supposed to be known by the printer and will determine which colour is printed.  A PDF spot colour also includes a RGB/CMYK information that may be used in cases where spot colours are not supported, eg, viewing the file with a PDF reader. It is up to the user to choose a colour that will approximate the spot colour as closely as possible.
 
More on PDF spot colors [http://partners.adobe.com/public/developer/en/pdf/PDFReference16.pdf here] (see pages 234 and 532)
 
Scribus provides a way to generate PDFs with spot colours: it is as simple as checking the corresponding checkbox in the '''Edit Colour''' window.
 
[[Image:Edit colour spot checkbox.png]]
 
==Industry standards for spot colours ==
 
There are several industry standards for spot colours, some of which are only used in certain areas of the world. The most widely used colour standard is produced by Pantone.
 
The [http://en.wikipedia.org/wiki/Pantone Pantone] colour set is a list of colours maintained by a company with the same name. Each colour corresponds to a name assigned by Pantone.
 
In terms of software, Pantone colours are treated as spot colours. To produce a document with Pantone colors, one has to:
 
# choose the colour(s) from a Pantone colour set
# mark the colours used in the document as spot colours, and assign the the correct Pantone names.
# assign them RGB or CMYK values (optional: doesn't affect how the final result comes from the press...)
# generate the PDF leaving the option "Convert spot colours to process colours" unchecked
# handle the PDF file to a print shop that supports Pantone
 
Although the Pantone colour tables contain RGB, CMYK and HTML values for each colour, the way the colour looks on screen (either in Scribus or a PDF viewer) is irrelevant in offset printing, because it will be printed according to its name.
 
It's of course better if the document on screen matches the printed version as closely as possible, so assigning RGB or CMYK values may help for visualisation, especially if the proof is printed on an inkjet or laserjet printer.
 
Some programs like Quark Xpress already come with built in lists of Pantone colour names and RGB/CMYK ''representations''. In terms of workflow this feature eliminates the need for steps 2 and 3. However, since there is no real on screen representation, the most important step, which is step 1, is indispensable.
 
The reason Scribus doesn't have such a table built-in, is caution regarding potential legal issues with Pantone. However one can build such a table for personal use and include it in Scribus.rc
 
Other vendors of colour standards:
 
*[http://www.hks-farben.de/ HKS], Germany
*[ANPA], United States
*[Toyo], Japan
*[DIC], Japan

Latest revision as of 23:37, 5 May 2006