Duotone

Duotone

[Michal Kvasnicka]

Dear friend!

The color separation discussion reminds me to ask one more question:
how can I handle duotone with ConTeXt.

Well, I'm not sure this is the
right English word. With `duotone' I mean documents typeset in two
colors, lets say black and green. Both color can be used with different
values (degree of light) and saturation (degree of black color). In
other
words, there can be used black, various grays, green, green-grays, ...
But all colors can be printed with only two direct colors.

Can such a separation can be done simply with ConTeXt? (Just two
slides: the black one and the green one.)

Many thanks.

M.K.

--
Economics is the only field in which two people can get a Nobel Prize
for saying exactly the opposite things.

Re: Duotone

[Hraban]

Michal Kvasnicka wrote:
> The color separation discussion reminds me to ask one more question:
> how can I handle duotone with ConTeXt.
> 
> Well, I'm not sure this is the
> right English word. With `duotone' I mean documents typeset in two

I think you mean "duplex" or just spot color separation.

I'm just working on a project with duplex photos, that is:
a greyscale picture with two different gradation curves
for two colors, e.g. black and brown (to look "old") or
black and grey (real duotone for artistical bw-photos).

Photoshop can save such duplex pictures as EPS.
But layout programs like QuarkXPress can't handle the two
included gradations and spot colors, so that they give
only a greyscale picture. For that purpose you must
save such pictures as "multi channel", so that two
separations are pre-defined. (CMYK would be a four-color-
multichannel) My colleague told me, that such would be
separatable by QXP (I never tried it myself).

If you're not talking about photos but only text or
vector graphics with two colors (black and a spot color),
it's something different.

With the mentioned "aurora" you can separate not only CMYK,
but even such spot colors from a PS file.
You must send the PS file once for every separation, every
time with an other header file that changes all other colors
to white. I tried it with my HP laserprinter, and it worked.
That means not automatically, that it will work with a film
typesetter / RIP.

Grüßlis vom Hraban!
---
http://angerweit.tikon.ch/lieder/
http://www.planet-interkom.de/fiee.visuelle/formelsammlung.html

Re: Duotone

[Taco Hoekwater]

Hraban wrote:
> 
> Michal Kvasnicka wrote:
> > The color separation discussion reminds me to ask one more question:
> > how can I handle duotone with ConTeXt.
> >
> > Well, I'm not sure this is the
> > right English word. With `duotone' I mean documents typeset in two
> 
> I think you mean "duplex" or just spot color separation.
> 
> I'm just working on a project with duplex photos, that is:

I thought the word was duotone for these images, and we just call it
two color printing here? Anyway, one of the easiest solutions for this 
is  using two of the four CMYK channels only, typically C and K. My 
printer was quite happy with these files.

Greetings, Taco

Re: Duotone

[Hraban]

Taco Hoekwater wrote:
> > > Well, I'm not sure this is the
> > > right English word. With `duotone' I mean documents typeset in two
> > I think you mean "duplex" or just spot color separation.
> > I'm just working on a project with duplex photos, that is:
> I thought the word was duotone for these images, and we just call it
> two color printing here? Anyway, one of the easiest solutions for this

I'm not really sure. I don't have a media dictionary.
I use(d) the words that are usual with Photoshop.

In German we say "Duoton(e)" only for black+grey (for better b+w photos),
but "Duplex" (Triplex etc.) for other combinations.
You can achieve an easy pseudo duplex effect (with QuarkXPress and
perhaps other programs) if you define fore- and background colors for
greyscale pictures.

> is  using two of the four CMYK channels only, typically C and K. My
> printer was quite happy with these files.

That's a good workaround -- I used to do it this way myself.
But if you need CMYK plus spot color its not possible.
And, as I wrote, multichannel should work, too.

Grüßlis vom Hraban!
---
http://angerweit.tikon.ch/lieder/
http://www.planet-interkom.de/fiee.visuelle/formelsammlung.html

Re: Duotone

[siep]

On  6 Dec, Hraban wrote:
> Taco Hoekwater wrote:
>> > > Well, I'm not sure this is the
>> > > right English word. With `duotone' I mean documents typeset in two
>> > I think you mean "duplex" or just spot color separation.
>> > I'm just working on a project with duplex photos, that is:
>> I thought the word was duotone for these images, and we just call it
>> two color printing here? Anyway, one of the easiest solutions for this
> 
> I'm not really sure. I don't have a media dictionary.
> I use(d) the words that are usual with Photoshop.
> 
> In German we say "Duoton(e)" only for black+grey (for better b+w photos),
> but "Duplex" (Triplex etc.) for other combinations.
> You can achieve an easy pseudo duplex effect (with QuarkXPress and
> perhaps other programs) if you define fore- and background colors for
> greyscale pictures.

I read in a book on Photoshop that duotones let you bring out more tonal
detail: you pick response curves for the different channels that
exaggerate contrast in different tonal ranges. In contrast, a fake
duotone will just lose you tonal detail. Which doesn't mean that you
should never use it, but you are trading decorative effect against
quality of rendering.

-- 
Siep Kroonenberg
siep@elvenkind.com

Re: Duotone

[Hans Hagen]

At 10:32 AM 12/7/00 +0100, siep@elvenkind.com wrote:
>On  6 Dec, Hraban wrote:
>> Taco Hoekwater wrote:
>>> > > Well, I'm not sure this is the
>>> > > right English word. With `duotone' I mean documents typeset in two
>>> > I think you mean "duplex" or just spot color separation.
>>> > I'm just working on a project with duplex photos, that is:
>>> I thought the word was duotone for these images, and we just call it
>>> two color printing here? Anyway, one of the easiest solutions for this
>> 
>> I'm not really sure. I don't have a media dictionary.
>> I use(d) the words that are usual with Photoshop.
>> 
>> In German we say "Duoton(e)" only for black+grey (for better b+w photos),
>> but "Duplex" (Triplex etc.) for other combinations.
>> You can achieve an easy pseudo duplex effect (with QuarkXPress and
>> perhaps other programs) if you define fore- and background colors for
>> greyscale pictures.
>
>I read in a book on Photoshop that duotones let you bring out more tonal
>detail: you pick response curves for the different channels that
>exaggerate contrast in different tonal ranges. In contrast, a fake
>duotone will just lose you tonal detail. Which doesn't mean that you
>should never use it, but you are trading decorative effect against
>quality of rendering.

There is something written about this in the [latest] pdf ref manual p 193,
there 
's also quadtone. 

Hans 
-------------------------------------------------------------------------
                                                  Hans Hagen | PRAGMA ADE
                      Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
 tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------

Re: Duotone

[Hraban]

siep@elvenkind.com wrote:
> I read in a book on Photoshop that duotones let you bring out more tonal
> detail: you pick response curves for the different channels that
> exaggerate contrast in different tonal ranges. In contrast, a fake
> duotone will just lose you tonal detail. Which doesn't mean that you
> should never use it, but you are trading decorative effect against
> quality of rendering.

That's true.
Real duotones, that enlarge your tonal range need someone who knows
what he's doing... (High end reproduction)
Colored duplex (triples, quadruplex) pictures that should only look
like something need a similar working method but are a rather different
task.

-- 
Grüßlis vom Hraban!
---
http://angerweit.tikon.ch/lieder/
http://www.planet-interkom.de/fiee.visuelle/formelsammlung.html

Re: Duotone

[Hans Hagen]

Concerning color, 

I must have some code somewhere which makes context separate itself by
tuning the color commands. Adding some color redef commands for ps is no
problem, but bitmaps can be. I'm still not sure how to support it, since
today i mostly produce pdf.  

Did anyone take a look at adobe inproduction, which does color sep for pdf? 

Hans
-------------------------------------------------------------------------
                                                  Hans Hagen | PRAGMA ADE
                      Ridderstraat 27 | 8061 GH Hasselt | The Netherlands
 tel: +31 (0)38 477 53 69 | fax: +31 (0)38 477 53 74 | www.pragma-ade.com
-------------------------------------------------------------------------