problem on choosing multichannel profile

[great_cyrus]

hi dears

i have an problem and that is that when i want to convert my design by my multi channel profile i cant do that and this option is not activate on my photoshop how i can activate that

edit====>convert to profile===>advanced===> i can not checked multi channel

[Mylenium]

It works as expected. You have to convert it to CMYK first and then you can add custom inks/ channels for printing.

Mylenium

[great_cyrus]

tnx for your reply but i have an icc profile and i have to convert my design by multi channel icc profile

[TomT-shirts]

I'm having the same problem. The answer marked as correct here is not correct. I tried converting to CMYK first, but I still can't convert to my multichannel ICC profile.

You can manually add custom spot color channels to a file that is in RGB, CMYK, or Greyscale mode. There is no reason to convert to CMYK first before manually adding spots.

Manually adding spots is NOT the same as converting to multichannel profile. What we're trying to do is the directions on this page:

Creative Suite * Working with color profiles

Under "Convert document colors to Multichannel, Device Link, or Abstract color profiles (Photoshop)"

I installed a multichannel ICC profile in /Library/Application Support/Adobe/Color/Profiles/, restarted Photoshop, but the "multichannel" option is still greyed out under "Advanced" in the "Convert to Profile" dialog.

[mschefers]

Has someone found out, why you cannot choose the multichannel option? I'm stuck in the same dialogue. I wat to separate colors of images to six channels (black, yellow, blue, red, green, brown) defined by the spot colors of a risograph. The only way i could convert yet was, not to choose multichannel but choose CMYK > Own CMYK > Custom Print colors > and then altered the cyan and magenta. But i could not add two more spot colors in there...

[Tina5E79]

I would like to add the following observation:
on a MacBook Pro with OS 10.14.6; Photoshop 22.5.6 and Radeon Pro 560X (GraphicsCard) everything works as expected. 
On an iMac Pro (2017) with OS 11.5.2; Photoshop 23.1.1 and Radeon Pro Vega 56 (Graphics Card) there is not the option to convert to multichannel ICC profiles. Why is that so? 

[Stephen_A_Marsh]

I don't know why one and not the other, it works for me if the MC ICC is installed (I don't have an example of it not working though):