Re: [artworks] PDF: When black isn't really black

  • From: Philip Pemberton <philpem@xxxxxxxxxxxxx>
  • To: artworks@xxxxxxxxxxxxx
  • Date: Tue, 09 May 2006 21:18:44 +0100

In message <b97742244e.martin@xxxxxxxxxxxxxxxxxxx>
          Martin Wuerthner <lists@xxxxxxxxxxxxxxx> wrote:

> Not surprisingly, the file does say pure black, so your PDF viewer is 
> messing things up, which is strange because the very same version of 
> Adobe Reader displays the file correctly here. It might be a global 
> Windows colour profile issue or something like that.

Apparently it's an Adobe Reader bug/misfeature. Officially, Reader doesn't
support CMYK conversions. It can display PDFs with CMYK colours, but it makes
a mess when it prints them. Adobe's recommendation seems to be "Buy Acrobat
Pro".

GhostScript / GSView seems to do a much better job of rendering ArtWorks
PDFs. GS's transparency calculations are closer to AW's, and CMYK
conversions seem to be more accurate. The only thing I noticed is it seems to
draw lines a bit thicker (or maybe it draws them after drawing the fill,
while AR draws the line first, then does the fill - no idea). Maybe it's
just me being stupid again.

I figured the cleaner solution (seeing as I was using the transparency tool
to create a 'segmented gradiented' effect, but not actually making use of
transparency) would be to use Phantasm to create a colour gradient palette,
then replace the transparency fills with solid colour. Worked quite nicely
actually.

I've just finished creating a business card template for the DECAdry
"Microperforated business card" kits (it's certainly right for the OCB 3260
kit, not sure about the others though). It'll be up on the Wiki in about 20
minutes, along with my notes on the CMYK issue.

Thanks.
-- 
Phil.                         | Kitsune: Acorn RiscPC SA202 64M+6G ViewFinder
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