how converting RGB to CMYK with text as 100% Black

[hassan_65]

Hi guys
I have a question that  how converting RGB to CMYK with text as 100% Black?
I think if I can make a script in Photoshop or something like that I will do it
But I dont know anything to make a script
for example a script
if  R= 255  G=255  B=255
convert it to 100% black
what do you think ? it will work ?

[Made in Taiwan]

Do you only have a pixel-based file like JPG or TIF? That's gonna be tough but you can try it. It would be easier if you had a PDF (I mean one with embedded fonts or at least outlined fontshad, not one created from the pixel file), because in that case you could use the built-in Acrobat change color tool or Pitstop if available.

[Tracy]

If it's not actual text, I don't think there is anyway of making it 100K
I'm not that smart tho :laugh:

[Joe]

The only way I can see even getting close is to make a CMYK profile with the black generation set at maximum black but that would be dangerous to apply blindly to all images.

[cpking]

For text it can be converted in fully 100% black without that it should not possible i think.

[mattbeals]

Convert with perceptual rendering intent, that will get the closest if not exactly what you want. Otherwise you need an device link  profile with GCR, or a device link that is smart enough to capture RGB/CMY blacks and keep them black. Generally though, perceptual will do what you want.

[swampymarsh]

Presuming an RGB image with a separate RGB black text layer, convert to CMYK without flattening then change the text to K only.

If you only have rasterised text in a separate layer, add a channel mixer adjustment layer to the file above the text layer, using a clipping mask group so that only the text is affected by the channel mixer adjustment layer. Then set the channel mixer to monochrome and mix the channels until you have 0c0m0y100k.

If you only have rasterised text in a flattened image, you would need a mask of the text to limit the monotone channel mixer effect to only the text.

Keep in mind that one may need a 1 or 2 pixel trap between the K only text and the CMY plates, unless there is a good amount of GCR in the conversion and K tones meet the solid K.

[Tracy]

Interesting, where is the channel mixer?
Photoshop is mysterious to me :laugh:

[Joe]

PShop menu===>Image===>Adjustments===>Channel Mixer.

[Tracy]

Thanks Joe, I also found Rt clicking on adjustment layer shows it too!
I'm a photoshop guru now :laugh:

[Joe]

You go girl!

[Ear]

I see the forecast for today is cloudy with a chance of mattbeals.

[Rodi]

I clean up a lot of logos with channel mixer, have several presets for this, also use Maximum ink, image dependent. In certain cases, it makes no diff, and with heavier K you get more stable color (not necessarily better). Some times I can run that, then curve out k in quarter tones. It's a crap shoot.