Noob questions Re: Cmyk and plugins

[Rickkins]

Hi guys.

 

Ok, here's the thing. Semi retired and want to reach a very limited audience, so I'm having some advertising postcards made.

 

As you can imaging, they want them to be in Cmyk.

 

Now, I've read a bit, and gather this can be done with plugins. So, two questions. Which plugin will be best for this...???

 

 

And, just as important, how do you install a plugin. Seriously, I checked all over the paint window, every setting, and I see nothing for 'plugins'.

 

What am I missing.

 

Thanks..!!

 

Edit: They ask for 300dpi too, if that's possible....

Edited January 27, 2016 by Rickkins

[Ego Eram Reputo]

The CYMK colorspace is different from paint.net's RGB colorspace. CYMK is subtractive - the less ink you use the more white you get (paper). RGB is additive, the more data you add the whiter colors get. If you leave color information off using RGB, the monitor will show black.

There is no 1:1 correlation between the two systems, so there is no plugin that can convert (in paint.net).

If your printer absolutely insists on CYMK find another. Commercial print houses these days should be able to handle RGB based images. I generally (successfully) submit images as PDF's. We have a plugin for that: Im(age)PDF.

RE: 300dpi - take the final size of your printed cards (in inches) and multiply by 300. Make your artwork this size in pixels.

[Rickkins]

Ok, thanks.

[MJW]

I'm sure there are subtleties I'm not aware of, but RGB and CYMK can be converted from one to another. There are free online tools to do it. (I can't vouch for the site, which I found with a Google search.)
 
At it's most basic, it's a simple coordinate transformation. Being too lazy to calculate it myself, I borrowed the formula from a website:
 
R' = R/255, G' = G/255, B' = B/255
The black key (K) color is calculated from the red (R'), green (G') and blue (B') colors: K = 1-max(R', G', B')
The cyan color ( C) is calculated from the red (R') and black (K) colors: C = (1-R'-K) / (1-K)
The magenta color (M) is calculated from the green (G') and black (K) colors: M = (1-G'-K) / (1-K)
The yellow color (Y) is calculated from the blue (B') and black (K) colors: Y = (1-B'-K) / (1-K)
 
Ed Harvey's Effects>Color>Extract Channel plugin does that, though it requires the process be done one channel at a time.
 
To do it right for particular hardware, the transformation probably needs to use the ICC profiles (which the site I linked to does do).

Edited January 27, 2016 by MJW

[Rickkins]

Thanks. ^

 

 

Still not sure how to make plugins work...

[MJW]

Fortunately for you, there's a whole topic devoted to that. The short version is that you download the plugin's zip file, usually by clicking on a link. Then you copy the plugin's DLL (contained in the zip file) into your "Program Files/paint.net/Effects" folder. The next time you run Paint.net, the plugin will appear in the Effects or Adjustments menu.

[Rickkins]

Oh outstanding. I kept looking for an "add addons" button some such.

 

Thanks mate.

[null54]

There is no 1:1 correlation between the two systems, so there is no plugin that can convert (in paint.net).

 

The Soft Proofing effect can export the current layer as a TIFF or JPEG with an embedded ICC profile.