How do I create a monochrome (b+w) profile in ACR?

[JBedfordPhoto]

I'm stumped.

I'm trying to create black+white custom profiles from a LUT that I exported from Lightroom (via a 3rd party plugin). Using this new LUT, I'm trying to create a custom profile within ACR. The conversion looks fine, but it's clear that my new profile is still a color profile. 

Because ACR and Lightroom both distinguish color profiles from monochrome ones, my question is how do I 'tell' my new profile to be monochrome and not color? Bonus points if you can also tell me how to add my copyright and contact info to the profile, too.

[TheDigitalDog]

LR and ACR's engine is RGB so you'll never get anything but RGB; even when all three values (each pixel) is equal values and thus neutral. There is no 'monochrome' per se, the RGB image can appear neutral but again, it's always RGB. 

[JBedfordPhoto]

Thanks @TheDigitalDog for the reply...I understand that the engines for both processors are RGB, however, one thing isn't yet clear to me; When creating a preset in ACR, for example, there's an option to "apply auto black and white mix" which is greyed out except when selecting an Adobe-made B+W profile at which point the option is available (not greyed out). 

If the option exists to "apply auto black and white mix" in the first place when creating a new preset, then shouldn't there be a way to create that preset without using one of Adobe's B+W profiles and use one my own instead? I mean, how did Adobe make these monochrome presets work in ACR and Lightroom if the programs are indeed RGB?

[JBedfordPhoto]

I'm still looking for an answer to my question here. Simplified, how did Adobe create a Monochrome Profile? I'm looking to do the same when creating B/W profiles of my own.

[JBedfordPhoto · Accepted solution]

So for those who are also stumped, I found a work-around. You must start by exporting your LUT with Adobe's monochrome profile first (with your own tweaks to curves, highlights, shadows, other parameters saved with LUTs). Create a new profile in ACR but be sure that the file you're working on (I'm working with RAWs) is set to Adobe Monochrome, first. Camera settings to include should be AdobeRGB1998. The look table should now be set to Adobe Monochrome by default. The LUT to select should be the one you just made a few steps ago. The 'space' should be AdobeRGB1998. I set the gamut to 'extend'. I left it at 32 and kept the range from 0-200. Save your profile. 

If all goes according to plan, the next time you open LR, your new profile should be available including the slider in which to increase or decrease the effect (in my experience, this slider sort of works like Multiply blending mode's opacity in Photoshop). 

Enjoy.