What can do to separate the file on to 2 colors

[OkiTech]

Hi guys, a question to a pre-press gurus:
Lets say I have a file, red and black, it could be saved as PDF from word or made in past as 2 color job but CMYK,
How can I manipulate it that some parts of it will become pure magenta and some pure black? So I can RIP out K+M and have it separated for plates? Is there such thing? Or what is the best practice? Most of our files are vector based out of Illustrator...
I tried asking my designer to create files in magenta+black to start with but then customers worry that it will be magenta at the end and I have a long way to explaining that magenta represents red and once plate is made I throw any ink I want....
Thanks in advance.

 

[Stephen Marsh]

If you are creating the art, then you have more control than with supplied art.

If the host software can work in spot colours, then the file should be setup as 2 colour only.

If the host software works with CMYK and If you have native files, one changes the native elements to suit - ensuring that the Black is solid black and that the CMYK Red is 100m100y. One can then only output the KM or KY plates as needed. While you or the client are changing things in the native software, you could just make the job 2 spot colour only.

If the host software only works with RGB such as MS Office, then you will need to have good PDF editing tools such as PitStop Pro to remap and recolour as needed.


Stephen Marsh

 

[jotterpinky]

I second Stephen, Ideally you would tell the designer to design the "Red" as a Pantone 185 or similar so the file looks like a red and black visually as well as when separating for plates. If this is not possible with the software the designer is using (sounds like MS Word) then you would need to change it after they've given it to you like you've described by changing to Magenta. Best practice would be to have your designed change the red to a spot color in Illustrator so it will separate correctly. However if you only have a PDF, and it's composed of vector elements as described your best bet would be to use Pitstop as Stephen mentioned to change the color...very simple if you create an action. One area where you might run into a bit more work would be if the document has raster objects as well and in that case you just might have to re-draw some of the elements from scratch since most raster objects would be composed of either RGB/CMYK objects.

 

[Stephen Marsh]

One area where you might run into a bit more work would be if the document has raster objects as well and in that case you just might have to re-draw some of the elements from scratch since most raster objects would be composed of either RGB/CMYK objects.

With PitStop Pro 12, it is possible to remap channels (does not matter if content is vector or raster), so the magenta channel can be globally remapped to a spot channel with no need to redraw or recreate anything. If the original image was RGB, then it would have to be converted to CMYK first before remapping - and one would need to ensure that the channel had the correct tones where needed (solids are actually 100% etc).


Stephen Marsh

 

[alfredflores]

You could do it manually...* Select all, then choose a channel in the Channels panel, then copy.* File - New, grayscale, paste, and flatten.* File - Save As, and there you go.* Repeat for each channel.