Mixing Pantone Colors - Just like CMYK channels???

Question

Hey Everyone,
I just signed up to the forum and had a look around. Hello everyone and I'm glad forums like this are around!
So, my question is hopefully one that is possible. I've looked elsewhere but can't find any difinitive answer or perhaps I haven't worded the question right but here it goes...
What I'd like to do [in photoshop] is treat 4 pantone colors just like CMYK channels. What I mean by that is that I would like to replace Cyan, Magenta, Yellow and Black with my own colors [pantone colors] and have them mix and act exactly like those channels. As in, when I open a full color image, and my pantone [or any color] channels or color profile is active, the full color image will react to those colors [with the blending of the colors].
Instead of 45% Cyan, 55% Magenta, 83% Yellow, and 2% Black in a given spot, it would be a mix of the 4 chosen colors [example: 45% pantone A, 55% Pantone B, 83% Pantone C, 2% Pantone D].
or to put it another way, if I were to color the background in, say, a blue, I would be able to use the "Info" panel to see how much of each pantone color was mixed to create that color. Obviously there would be a limit to the colors I could create based on the pantone colors I select.
I don't want to do anything printing wise with this technique. I am looking at it solely as an onscreen viewer or perhaps use it in some manner for screen printing.
Anybody have any ideas on how to achieve this?
Many thanks in advance.

Answer 1

Beyond setting up a multichannel document there is no magic. And it is still merely an approximation because some colors can neither be simulated on-screen nor actually printed that way. That ultimately is the whole point - PS can't simulate anything that is impossibole in the "real world" and expressed as a color profile. Anyway, I have the feeling that you have a wrong understanding what spot colors actually are/ are meant for. They simply won't respond like the basic CMYK channels because their actual inks don't behave that way. Your ink percentages will never represent anything equivalent to a mathematical mixing formula as when using RGB or CMYK, instead they are the inks color multiplied by the opacity. In case of an on-screen simulation/ proof they would not even necessarily include effects that happen due to spectral absorption when light travels through the inks or the inks mixing chemically/ physically at the pigment level. It really doesn't exactly make sense for what you have possibly in mind due to the aforementioned specifics and limitations of the simulation. One could even go so far as to craft everything in red on screen and then swap the color for green during the printing process, assuming only 100% opacities are used. That is to say spot colors are often more considered like masks that constrain the actual ink to certian areas and when you think of it that way, you may begin to understand how and why your grand plan may fall apart. Of course we don't know what your artwork looks like, so it may work, after all, but I realyl think you are heading in the wrong direction, dreaming up something that doesn't exist.
Mylenium