How can i? GCR-Separation with custom six-color-profile for RISOGRAPHY

[mschefers]

Hello,

i own a risograph, very old, very analog. I can print five spot colors (red, blue, yellow, green and brown) and black. But its not connected to a computer. Instead I have to print each color separated, one at a time by feeding my scanning unit with greyscaled originals. So heres what i want to do:

I want to separate the colors of an image into multichannel with GCR, each channel representing my spot colors, so feed the RISO. I can look up the Pantone or RGB codes of my riso colors, but i cant use them, because the option multichannel is greyed out in the "Convert to profile" dialogue. I can just use CMYK > Own CMYK > Custom colors and change them. (Screenshot) So i end up with four colors.

What do i do wrong? Or ist this even thought wrong?

Thanks!

[Stephen_A_Marsh]

Multichannel profiles are created by commercial ICC profile creation software. I am guessing that you don’t have a budget that extends into thousands of dollars for such software for this hobby…

Can you post a scan or photo of an original colour image that contains a full range of colour and tone, with a version that has been successfully separated and output on the risograph?

https://medium.com/@geraldpkelley/my-adventure-in-risograph-printing-d717db2c0936

Exploriso: Using MultiColor Profiles for the Risograph | duplo.press

https://colorlibrary.ch/how-to-install/

[mschefers]

Thanks for your reply.

Do you mean there is no option to "make" an own 6-C-profile in photoshop? Or that it does not make any sense to do it without spectrometer and other software?

I know that ICC profiles for "real" color management is cost expensive. And i dont hope to get a perfect and stable printing process matching all colors. I just want to understand what it does and see what i can do.

I know DuploPress and Colorlibrary. Explorisos webshop for profiles does not work and he did not reply. And colorlibrary does not offer a profile for those colors. I dont have pink for false cmyk. So i thought i could set up a multichannel and try some settings to fit the colors and machine i use.

I will upload a scan and an original when i have it. If it had been successfull, maybe i would not write this

[kayr23628964]

Did you ever come up with a solution to this? I have been playing around with the custom colors cmyk conversion but it keeps crashing my photoshop.