From mboxrd@z Thu Jan 1 00:00:00 1970 X-Msuck: nntp://news.gmane.io/gmane.comp.tex.context/55155 Path: news.gmane.org!not-for-mail From: Peter Rolf Newsgroups: gmane.comp.tex.context Subject: Re: Bug with overprinting in Mark II/IV? Date: Fri, 11 Dec 2009 19:23:09 +0100 Message-ID: <4B228E0D.5080402@gmx.net> References: <874onxhdu7.fsf@sopos.org> <4B224BE7.4010203@gmx.net> <87zl5pfp47.fsf@sopos.org> <4B2282F2.1000200@gmx.net> <87zl5pe6lx.fsf@sopos.org> Reply-To: mailing list for ConTeXt users NNTP-Posting-Host: lo.gmane.org Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2078445135==" X-Trace: ger.gmane.org 1260555825 23078 80.91.229.12 (11 Dec 2009 18:23:45 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Fri, 11 Dec 2009 18:23:45 +0000 (UTC) To: mailing list for ConTeXt users Original-X-From: ntg-context-bounces@ntg.nl Fri Dec 11 19:23:38 2009 Return-path: Envelope-to: gctc-ntg-context-518@m.gmane.org Original-Received: from balder.ntg.nl ([195.12.62.10]) by lo.gmane.org with esmtp (Exim 4.50) id 1NJA9Q-0001hU-7n for gctc-ntg-context-518@m.gmane.org; Fri, 11 Dec 2009 19:23:36 +0100 Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 17A84C9C87; Fri, 11 Dec 2009 19:23:36 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id n0rMVWpahQC6; Fri, 11 Dec 2009 19:23:23 +0100 (CET) Original-Received: from balder.ntg.nl (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 562D4C9C35; Fri, 11 Dec 2009 19:23:23 +0100 (CET) Original-Received: from localhost (localhost [127.0.0.1]) by balder.ntg.nl (Postfix) with ESMTP id 2B36EC9C35 for ; Fri, 11 Dec 2009 19:23:22 +0100 (CET) X-Virus-Scanned: Debian amavisd-new at balder.ntg.nl Original-Received: from balder.ntg.nl ([127.0.0.1]) by localhost (balder.ntg.nl [127.0.0.1]) (amavisd-new, port 10024) with LMTP id WAM370DhHLo2 for ; Fri, 11 Dec 2009 19:23:09 +0100 (CET) Original-Received: from mail.gmx.net (mail.gmx.net [213.165.64.20]) by balder.ntg.nl (Postfix) with SMTP id CE8B3C9B49 for ; Fri, 11 Dec 2009 19:23:09 +0100 (CET) Original-Received: (qmail invoked by alias); 11 Dec 2009 18:23:09 -0000 Original-Received: from i577BEF4D.versanet.de (EHLO [192.168.1.3]) [87.123.239.77] by mail.gmx.net (mp054) with SMTP; 11 Dec 2009 19:23:09 +0100 X-Authenticated: #24293357 X-Provags-ID: V01U2FsdGVkX18d28IAECMdA2M3pIM70LaZWP44fAC05mOdHLL8rZ s6RoK2U3QXUyxO User-Agent: Thunderbird 2.0.0.23 (Windows/20090812) In-Reply-To: <87zl5pe6lx.fsf@sopos.org> X-Y-GMX-Trusted: 0 X-FuHaFi: 0.59,0.57 X-BeenThere: ntg-context@ntg.nl X-Mailman-Version: 2.1.12 Precedence: list List-Id: mailing list for ConTeXt users List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Original-Sender: ntg-context-bounces@ntg.nl Errors-To: ntg-context-bounces@ntg.nl Xref: news.gmane.org gmane.comp.tex.context:55155 Archived-At: This is a multi-part message in MIME format. --===============2078445135== Content-Type: multipart/alternative; boundary="------------010004030507010201090709" This is a multi-part message in MIME format. --------------010004030507010201090709 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Oliver Heins schrieb: > Peter Rolf writes: > > >> Oliver Heins schrieb: >> >>> Yes, I noticed that, too. But to me it looks like it is first knocked >>> out in the pdf, and then the overprint flag is set. >>> >>> >>> >> Good point. In that case the text must be set twice, as knockout and >> overprint can't coexist. I have looked into the uncompressed mkii PDF >> (\nopdfcompression) and I can not see any obvious flaw. The parts are >> clearly separeted by '/GSknockout gs' and '/GSoverprint gs', the black >> text is not set twice. >> >> Just an idea: the colorspace of the picture is RGB, the text is set in >> CMYK. Maybe the mixed color spaces mess up things here. >> > > But shouldn't the same effect be seen with other colors than black then, > too? And it only happens with black, and I think it happens even when > you do it within a cmyk-only document: > > I get the same 'kind of knockedout' text as in the other example... but the black text is set as /DeviceGray and not /DeviceCMYK (k-component). You can make this visible by using 'Vorschau: Separiert' with the option 'Einblenden: Nicht-DeviceCMYK'. I think this is just a limitation of the previewer. You can define your own cmyk black with \definecolor[myblack][k=1]. I bet that the knockedout effect will vanish with cmyk black (untested). > Can you test the following? My Acrobat is on a machine without net, and > my usb stick broke within the experiments. > > prepress mess + bad luck => *have a break and enjoy your weekend* :) > Best regards, > olli > > \setupcolors[state=start, cmyk=yes, rgb=no] > > \starttext > > {\bfb\setstrut > \startoverprint > \framed > [background=color,backgroundcolor=magenta, > foregroundcolor=yellow,align={lohi,middle}, > frame=off,width=3.5cm,height=3cm] > {overprint\\\property[knockout]{knockout}}% > \stopoverprint > \framed > [background=color,backgroundcolor=magenta, > foregroundcolor=yellow,align={lohi,middle}, > frame=off,width=3.5cm,height=3cm] > {knockout\\\property[overprint]{overprint}}}% > > {\bfb\setstrut > \startoverprint > \framed > [background=color,backgroundcolor=magenta, > foregroundcolor=black,align={lohi,middle}, > frame=off,width=3.5cm,height=3cm] > {overprint\\\property[knockout]{knockout}}% > \stopoverprint > \framed > [background=color,backgroundcolor=magenta, > foregroundcolor=black,align={lohi,middle}, > frame=off,width=3.5cm,height=3cm] > {knockout\\\property[overprint]{overprint}}}% > > \stoptext > > > --------------010004030507010201090709 Content-Type: text/html; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Oliver Heins schrieb: 
Peter Rolf <indiego@gmx.net> writes:

  
Oliver Heins schrieb:
    
Yes, I noticed that, too.  But to me it looks like it is first knocked
out in the pdf, and then the overprint flag is set.

  
      
Good point. In that case the text must be set twice, as knockout and
overprint can't coexist. I have looked into the uncompressed mkii PDF
(\nopdfcompression) and I can not see any obvious flaw. The parts are
clearly separeted by '/GSknockout gs' and '/GSoverprint gs', the black
text is not set twice.

Just an idea: the colorspace of the picture is RGB, the text is set in
CMYK. Maybe the mixed color spaces mess up things here.
    

But shouldn't the same effect be seen with other colors than black then,
too?  And it only happens with black, and I think it happens even when
you do it within a cmyk-only document:
I get the same 'kind of knockedout' text as in the other example...
but the black text is set as /DeviceGray and not /DeviceCMYK (k-component). You can make this visible by using
'Vorschau: Separiert' with the option 'Einblenden: Nicht-DeviceCMYK'.

I think this is just a limitation of the previewer. You can define your own cmyk black with \definecolor[myblack][k=1]. I bet that the knockedout effect will vanish with cmyk black (untested).

Can you test the following?  My Acrobat is on a machine without net, and
my usb stick broke within the experiments.
prepress mess + bad luck => *have a break and enjoy your weekend* :)

Best regards,
 olli

\setupcolors[state=start, cmyk=yes, rgb=no]

\starttext

{\bfb\setstrut
\startoverprint
\framed
[background=color,backgroundcolor=magenta,
foregroundcolor=yellow,align={lohi,middle},
frame=off,width=3.5cm,height=3cm]
{overprint\\\property[knockout]{knockout}}%
\stopoverprint
\framed
[background=color,backgroundcolor=magenta,
foregroundcolor=yellow,align={lohi,middle},
frame=off,width=3.5cm,height=3cm]
{knockout\\\property[overprint]{overprint}}}%

{\bfb\setstrut
\startoverprint
\framed
[background=color,backgroundcolor=magenta,
foregroundcolor=black,align={lohi,middle},
frame=off,width=3.5cm,height=3cm]
{overprint\\\property[knockout]{knockout}}%
\stopoverprint
\framed
[background=color,backgroundcolor=magenta,
foregroundcolor=black,align={lohi,middle},
frame=off,width=3.5cm,height=3cm]
{knockout\\\property[overprint]{overprint}}}%

\stoptext

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