setting the color of cropmarks

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mf

19 Dec 2019 19 Dec '19

4:41 p.m.

Hello list, \setuplayout[marking=on] typesets crop marks that are in grayscale black. Can I change their color, in particular into a CMYK black (0,0,0,1.0)? Thanks, Massi

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Henning Hraban Ramm

19 Dec 19 Dec

6:07 p.m.

Am 2019-12-19 um 16:41 schrieb mf :

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Hello list,

\setuplayout[marking=on] typesets crop marks that are in grayscale black.

Can I change their color, in particular into a CMYK black (0,0,0,1.0)?

There’s no parameter, and I don’t understand how the markings are set in https://source.contextgarden.net/tex/context/base/mkiv/strc-mar.mkiv Maybe you see more… There’s an example for custom marks at the bottom. It would also make sense to use CMYK register color (1,1,1,1). Best, Hraban

mf

6:24 p.m.

Il 19/12/19 18:07, Henning Hraban Ramm ha scritto:

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Am 2019-12-19 um 16:41 schrieb mf :

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Hello list,

\setuplayout[marking=on] typesets crop marks that are in grayscale black.

Can I change their color, in particular into a CMYK black (0,0,0,1.0)?

There’s no parameter, and I don’t understand how the markings are set in https://source.contextgarden.net/tex/context/base/mkiv/strc-mar.mkiv

No, that's about markings, a different thing. I think the right file is page-mrk.mkiv. The crop marks are made with MP. I'm looking into it...

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Maybe you see more… There’s an example for custom marks at the bottom.

It would also make sense to use CMYK register color (1,1,1,1).

I do agree. Massi

Wolfgang Schuster

6:39 p.m.

mf schrieb am 19.12.2019 um 18:24:

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Il 19/12/19 18:07, Henning Hraban Ramm ha scritto:

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Am 2019-12-19 um 16:41 schrieb mf :

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Hello list,

\setuplayout[marking=on] typesets crop marks that are in grayscale black.

Can I change their color, in particular into a CMYK black (0,0,0,1.0)?

There’s no parameter, and I don’t understand how the markings are set in https://source.contextgarden.net/tex/context/base/mkiv/strc-mar.mkiv

No, that's about markings, a different thing. I think the right file is page-mrk.mkiv. The crop marks are made with MP. I'm looking into it...

There is no option to change the color for the rules and the only option you have is to use color conversion. \setupcolors[cmyk=yes,rgb=no] If you need more control you can create your own marks and add them as background for the page. Wolfgang

mf

7:11 p.m.

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There is no option to change the color for the rules and the only option you have is to use color conversion.

\setupcolors[cmyk=yes,rgb=no]

I do have this setup, but it produces grayscale crop marks. I was told by two different printshops that grayscale raises problems with recent versions of PDF software (verification? imposition? I've not asked), that complains about that, because it treats grayscale as RGB, splitting it on C, M and Y channels, instead of mapping it only to the K channel.

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If you need more control you can create your own marks and add them as background for the page.

I've seen there's something about that in the mailing list history. I'll look into that. BTW, the MP file producing the marks is metapost/context/base/mpiv/mp-crop.mpiv Massi

Henning Hraban Ramm

7:46 p.m.

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Am 2019-12-19 um 19:11 schrieb mf :

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There is no option to change the color for the rules and the only option you have is to use color conversion. \setupcolors[cmyk=yes,rgb=no] I do have this setup, but it produces grayscale crop marks.

I was told by two different printshops that grayscale raises problems with recent versions of PDF software (verification? imposition? I've not asked), that complains about that, because it treats grayscale as RGB, splitting it on C, M and Y channels, instead of mapping it only to the K channel.

I’d regard that a misconfiguration on their side. Maybe it helps to define the output intent: https://wiki.contextgarden.net/Command/setupbackend https://wiki.contextgarden.net/PDFX

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If you need more control you can create your own marks and add them as background for the page. I've seen there's something about that in the mailing list history. I'll look into that.

BTW, the MP file producing the marks is

metapost/context/base/mpiv/mp-crop.mpiv

Sorry for mixing up marks and markings.

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Am 2019-12-19 um 19:08 schrieb Hans Hagen :

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Can I change their color, in particular into a CMYK black (0,0,0,1.0)?

Just curious ... isn't gray (g G) equivalent enough? I assume that a cmyk prepress document can have gray scale images too.

Grayscale color space is device dependent, as well as CMYK and RGB color definitions without a profile; it should be the same as black CMYK channel, but needs not to.

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It would also make sense to use CMYK register color (1,1,1,1). I do agree. I might agree if I know what is meant here.

Massi said the crop marks are defined in grayscale black, but wants CMYK black. In layout programs crop and registration marks are usually set in a color named "Registration" (not register, my mistake) or the like, and it maps to all color plates, i.e. mostly CMYK 1,1,1,1, but also spot colors. You need that for manual film montage. Greetlings, Hraban

Hans Hagen

8:21 p.m.

On 12/19/2019 7:46 PM, Henning Hraban Ramm wrote:

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Massi said the crop marks are defined in grayscale black, but wants CMYK black. In layout programs crop and registration marks are usually set in a color named "Registration" (not register, my mistake) or the like, and it maps to all color plates, i.e. mostly CMYK 1,1,1,1, but also spot colors. You need that for manual film montage.

So what is 1,1,1,1 ? Quite some mixed ink i guess? Kind of brown + black? I can add some control over these cropmark colors by using symbolic names (later). Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

Henning Hraban Ramm

9:11 p.m.

Am 2019-12-19 um 20:21 schrieb Hans Hagen :

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On 12/19/2019 7:46 PM, Henning Hraban Ramm wrote:

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Massi said the crop marks are defined in grayscale black, but wants CMYK black. In layout programs crop and registration marks are usually set in a color named "Registration" (not register, my mistake) or the like, and it maps to all color plates, i.e. mostly CMYK 1,1,1,1, but also spot colors. You need that for manual film montage.

So what is 1,1,1,1 ? Quite some mixed ink i guess? Kind of brown + black?

C,M,Y,K each 100% (no relationship to 1,1,1-Trichloroethane)

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I can add some control over these cropmark colors by using symbolic names (later).

That would be nice. If you print on an office printer and cut yourself, it might make sense to use very light (e.g. yellow) crop marks. Since I also sometimes need folding marks, I need to look into that sourcecode… Hraban

mf

20 Dec 20 Dec

1:18 p.m.

This is a dirty hack to change the color of the crop marks and the page number at the corner of a page when \setuplayout[marking=on]. Edit the file: tex/texmf-context/metapost/context/base/mpiv/mp-crop.mpiv in the distribution, changing two lines: ----- (here i'm reproducing only the last part of the file) ------ def page_marks_add_lines(expr width, height, length, offset, nx, ny, boxtoo) = % todo: namespace pickup pencircle scaled 1/2 ; interim linecap := squared ; interim linejoin := butt ; path page ; page := fullsquare xscaled width yscaled height ; path more ; more := page enlarged (offset+length/2,offset+length/2) ; % draw crop_marks_lines(page,length,offset,nx,ny,boxtoo) ; draw crop_marks_lines(page,length,offset,nx,ny,boxtoo) withcolor (0,0,0,1) ; setbounds currentpicture to page ; enddef ; def page_marks_add_number(expr width, height, length, offset, n) = % todo: namespace pickup pencircle scaled 1/2 ; interim linecap := squared ; interim linejoin := butt ; path page ; page := fullsquare xscaled width yscaled height ; path more ; more := page enlarged (offset+length/2,offset+length/2) ; for s=llcorner more, lrcorner more, ulcorner more, urcorner more : % draw textext(decimal n) shifted s ; draw textext(decimal n) shifted s withcolor (0,0,0,1) ; endfor ; setbounds currentpicture to page ; enddef ; ----------------------------------------------------------- You must add "withcolor (0,0,0,1)" before the final semicolon to two lines: the ones that i commented out with a leading "%". In case you wanted crop marks in all the CMYK channels, add "withcolor (1,1,1,1)". Once you modify the file, remake the format with context --make A parametric solution would let you define a "registration" color in ConTeXt, then map it to the corresponding "withcolor" instruction in mp-crop.mkiv. I'm sure there are already functions to do that mapping. It's the difficult part (at least for me) when Hans talks about adding "some control over these cropmark colors by using symbolic names". Massi

Hans Hagen

19 Dec 19 Dec

7:08 p.m.

On 12/19/2019 6:24 PM, mf wrote:

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Il 19/12/19 18:07, Henning Hraban Ramm ha scritto:

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Am 2019-12-19 um 16:41 schrieb mf :

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Hello list,

\setuplayout[marking=on] typesets crop marks that are in grayscale black.

Can I change their color, in particular into a CMYK black (0,0,0,1.0)?

Just curious ... isn't gray (g G) equivalent enough? I assume that a cmyk prepress document can have gray scale images too.

...

...
There’s no parameter, and I don’t understand how the markings are set in https://source.contextgarden.net/tex/context/base/mkiv/strc-mar.mkiv

No, that's about markings, a different thing. I think the right file is page-mrk.mkiv. The crop marks are made with MP. I'm looking into it...

...
Maybe you see more… There’s an example for custom marks at the bottom.

It would also make sense to use CMYK register color (1,1,1,1).

I do agree. I might agree if I know what is meant here.

Hans ----------------------------------------------------------------- Hans Hagen | PRAGMA ADE Ridderstraat 27 | 8061 GH Hasselt | The Netherlands tel: 038 477 53 69 | www.pragma-ade.nl | www.pragma-pod.nl -----------------------------------------------------------------

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Hans Hagen
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mf
Wolfgang Schuster

setting the color of cropmarks

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