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Author Topic: spot color images becomes CMYK  (Read 9565 times)

mnawij

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spot color images becomes CMYK
« on: January 14, 2014, 05:44:57 am »
I have 2 different images (1bit) black/white .png files with transparent backgrounds in my design and I applied a different spot color to each.  When I export to .ps/.eps then convert to .pdf with Adobe Distiller AND exporting to .pdf straight from Scribus versions 1.4, 1.5, and PDFX (with all color management turned on), the images get converted to CMYK (I confirmed this with Enfocus Pitstop) after trying to print.  I apply the spot color by using image effects-->colorize.  Is this possible?  My printshop prints 90% spot colors and this is a must for my workflow...I have done this hundreds of times from InDesign with no problems.  This is not an InDesign vs. Scribus, but is possible in pdf creation is the only reason I bring this point up.

Thanks.

PS and yes I did not check the convert spot to CMYK.

Files attached.

Scribus 1.4.3 on Mac OS X 10.8
« Last Edit: January 14, 2014, 05:46:52 am by mnawij »

Nermander

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Re: spot color images becomes CMYK
« Reply #1 on: January 14, 2014, 08:16:15 am »
Are you 100% sure you didn't tick the Convert spot colors to CMYK checkbock?

See second image here
http://documentation.scribus.net/index.php/Spot_Colors

I've never used spot colors other than for a few test pages so I'm not sure how the colorize function works with spot colors.

utnik

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Re: spot color images becomes CMYK
« Reply #2 on: January 14, 2014, 09:21:56 am »
hi mnawij

Are you 100% sure you didn't tick the Convert spot colors to CMYK checkbock?

afaik by default this box is checked – you have to uncheck it to keep your spot colors!

utnik

leaf

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Re: spot color images becomes CMYK
« Reply #3 on: January 14, 2014, 05:59:54 pm »
mnawij
It is deficiency in Scribus. More is here http://bugs.scribus.net/my_view_page.php
But are three separate tricks.
1. Convert Your raster in vector graphisc. (problem is only for bitmaps)
2. Use Cyan as Your one Pantone blue, and Magenta as second Red Pantone. Next tell in PrintHouse to replace Magenta and Cyan in your spot colors.
3. I attach my solution, for analysis. (important to prepare other way bitmaps)
« Last Edit: January 14, 2014, 06:03:54 pm by leaf »

utnik

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Re: spot color images becomes CMYK
« Reply #4 on: January 14, 2014, 08:55:50 pm »
hi leaf

could you provide a link to the related bug report – i didn't know about this, but i'm interested in it…

utnik

mnawij

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Re: spot color images becomes CMYK
« Reply #5 on: January 14, 2014, 09:00:59 pm »
Thanks leaf

Yes I know about converting to vector, basically it boils down to time, $$$, or hardcopy artwork that we have had for 50+ years.  I use vectormagic.com for the conversions.
Yes I did know the trick about coloring with Cyan/Magenta/Yellow Plates, but I have had vendors reject it or their designers did not understand what to do even with clear explanations.
Do you have the bug # so I can follow it, I tried a quick search for with no luck.

mnawij

mnawij

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Re: spot color images becomes CMYK
« Reply #6 on: January 14, 2014, 09:17:13 pm »
utnik, here is the bug:

Issue # 0003743

I am new to the forums, how do you add comments in the bug tracker system, this problem has been around since 1.3 it looks like.  I thought I read that PDF 'printing' related issues gets high priority.  I would think that this is a pdf print related issue.

mnawij

utnik

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Re: spot color images becomes CMYK
« Reply #7 on: January 14, 2014, 10:14:54 pm »
hi mnawij

thanks for the bug nr.
i'll take a closer look at it, when i can find some time – looks like a complex of many color related bugs…

…how do you add comments in the bug tracker system…

you need an acount to mantis bug tracker – but afaik there are some problems for new members to log in…

utnik

Nermander

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Re: spot color images becomes CMYK
« Reply #8 on: January 15, 2014, 08:13:53 am »
Not sure if it was the same bug I found, the problem I read about was that it is a matter of what image effects can be applied to an image.

If you want to use spot colors, a lot of the image effects need to be disabled (because they won't work on images with spot colors). So there has to be some way to let the user choose: Do you want to be able to use the other image effects or do you want the image to stay duo-tone?

leaf

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Re: spot color images becomes CMYK
« Reply #9 on: January 15, 2014, 11:11:27 am »
fourth solution yet (but is not free, needful photoshop)
step1  in photoshop prepare Your bitmaps CMYK + spot, if necessary cmyk channels are empty
step 2 save as pdf
step 3 place Your pdf in Scribus in Your project.
step 4 save as pdf (important - embed PDF experimentall)

I attach sample file.

utnik

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Re: spot color images becomes CMYK
« Reply #10 on: January 15, 2014, 11:26:52 am »
…it is a matter of what image effects can be applied to an image.

…there has to be some way to let the user choose…

there's no such choice yet – it's one of the reasons why this bug is still open…

utnik

Nermander

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Re: spot color images becomes CMYK
« Reply #11 on: January 15, 2014, 03:48:06 pm »
That's what I meant:)

To make it possible to not convert to CMYK there has to be some way for the user to choose.

mnawij

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Re: spot color images becomes CMYK
« Reply #12 on: January 16, 2014, 03:52:06 am »
Nermander

The choice is made when a selected spot color is applied to an object.  I am not sure of all the background issues with color programming, but the pdf file type already accepts this within its formatting otherwise Quark, Corel, Photoshop, Illustrator, InDesign would not be able to do it...  Most of these applications can even apply spot colors to Greyscale images, not just single bit b/w images.  I deal with several graphic designers on a monthly basis, and I would say at least 20%+ of the files that I need to print have spot colors applied to bitmaps, but I live in the world of spot color printing.
----------------

Utnik

Thanks for the trick with photoshop-->pdf placement, I will have to give that a try sometime in the next week or so, but my ultimate goal is to use only FOSS software.

utnik

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Re: spot color images becomes CMYK
« Reply #13 on: January 16, 2014, 07:00:17 am »
hi mnawij

Utnik

Thanks for the trick with photoshop-->pdf placement…

it wasn't me – you should send the flowers to leaf instead!

utnik

Nermander

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Re: spot color images becomes CMYK
« Reply #14 on: January 16, 2014, 08:23:59 am »
The choice is made when a selected spot color is applied to an object. 

That would mean that the code would effectively need disable all non-compatible Image Effects when the user selects a spot color for colorize. Then the user must somehow be informed of this, because otherwise this forum and the mailing list will be flooded with "Why are the Image Effects disabled??"-questions.