Re: CMYK separations on Adobe Photoshop

Again, this is just a RGB printing not a conversion to CYMK to then print
the Cyan layer with the Cyan pigment or modify it first by applying curves.
It is not crazy, it's just the way of how to print RGB.
The question is:
"Hi list, there is a easy way, or not easy, to make cmyk separations on
photoshop other than change image mode to cmyk. I want to obtain the
separation channels as layers in order to apply curves over every layer
independently and save it as different files."

How can you apply curves to Cyan? Not to Red because they behave different
as complemetary or not?
Giovanni

----- Original Message -----
Wrom: KPNKMBIPBARHDMNNSKVFVWRKJVZCMHVI
To: <alt-photo-process-l@sask.usask.ca>
Sent: Saturday, October 30, 2004 4:42 AM
Subject: RE: CMYK separations on Adobe Photoshop

> You print the Red channel with cyan, the Green with Magenta, and the
> Blue with Yellow.
> It sounds crazy but it's true!!!
> Cheers
> Kate
>
> -----Original Message-----
> Wrom: BGDADRZFSQHYUCDDJBLVLMHAALPTCXLYRWTQTIPWIGYOKSTT
> Sent: Saturday, 30 October 2004 4:48 p.m.
> To: alt-photo-process-l@sask.usask.ca
> Subject: Re: CMYK separations on Adobe Photoshop
>
>
> Sorry, but...
> How do you get the Cyan channel from a RGB file without going to CMYK?
> Isn't this the question? How do you get the Cyan colors? Giovanni
>
>
> ----- Original Message -----
> Wrom: ZXUWLSZLKBRNVWWCUFPEGAUTFJMVRESKP
> To: <alt-photo-process-l@sask.usask.ca>
> Sent: Friday, October 29, 2004 10:22 AM
> Subject: Re: CMYK separations on Adobe Photoshop
>
>
> > I forgot to mention a fairly obvious thing: once you have the channel
> > saved as a positive grayscale file you have to invert the positive to
> > a negative. This can be done under Image--> Adjustments-->Invert or
> > by having the printer set to invert the files during printing. I also
>
> > flip the image horizontally when printing so that the ink surface is
> > next to the emulsion of the paper.
> >
> > By sheer coincidence, yesterday and today I have been testing
> > separation negatives made for gum printing on a new Epson 2200 printer
>
> > using both the CMYK mode and the RGB method I described earlier. I'll
>
> > scan the prints as soon as they dry today and put them online. Once
> > on the web, I'll post the URL in case you wish to see a visual
> > comparison of the results of both methods.
> >
> > Joe
> >
> > >>> jsmigiel@kvcc.edu 10/29/04 8:56 AM >>> mgalanmolina@hotmail.com
> > >>> 10/29/04 5:57 AM >>>
> > Hi list, there is a easy way, or not easy, to make cmyk separations on
>
> > photoshop other than change image mode to cmyk. I want to obtain the
> > separation channels as layers in order to apply curves over every
> > layer independently and save it as different files.
> >
> > Thanks
> >
> > Manuel, from Spain
> >
> > Wih an RGB file (e.g., image.psd), open the channels window and select
>
> > a channel. For example, select the red channel. Then change the mode
>
> > to grayscale and discard the other channels. At this point, ***be
> > sure to rename the file*** (e.g., image_RED.psd). You now have a
> > grayscale positive of the Red channel and you have the original file
> > still intact. Do the same with the other channels (G+B). Then, using
>
> > the original file, change the mode to grayscale (or desaturate the RGB
>
> > file) and rename it for the black channel.
> >
> > Be aware that this set of negatives will be distorted in terms of
> > color printing characteristics compared to those made using the CMYK
> > mode and selecting those individual channels for negatives. The info
> > preserved just isn't the same, but can be interesting nontheless.
> >
> > Also, why not use the channel mixer (Image-->Adjustments-->Channel
> > Mixer
> > IIRC) to get the effects you desire in RGB and then switch to CMYK and
> > print out the separations?
> >
> > Joe
> >
> >
>
> ---
> Incoming mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.786 / Virus Database: 532 - Release Date: 29/10/2004
>
>
> ---
> Outgoing mail is certified Virus Free.
> Checked by AVG anti-virus system (http://www.grisoft.com).
> Version: 6.0.786 / Virus Database: 532 - Release Date: 29/10/2004
>
>
>
Received on Sat Oct 30 09:03:10 2004