Spot color previews affected by RGB channels in CC2017

[shanep66323295]

Hi,

  I make spot color separations for screenprinting by building spot color channels over RGB and then converting to and saving as a multichannel DCS/EPS.

I will have a solid substrate color spot color channel that is first in the order and then more spot color channels under that.  When I wanted to preview my work, I just set all of the spot color channels on and the substrate color masked the RGB so I could see the results of my work in just the channel view. The preview with just the spot colors on would not change whether the RGB channels were on or not

Now, after updating to CC2017.1.0, the channel preview changes when I toggle the RGB channels on or off. They never did this before.  In our office we have older versions running and the same file behaves correctly, but on my station with the latest, I get different blending depending on whether the RGB preview is toggled on or off. It doesn't even matter if there is anything on the RGB channels to blend. It behaves the same whether there is any artwork on any layer or not. It behaves this way on older files created with older versions on the my updated sattion, but on other stations running older, it doesn't

It only does this in RGB. If I convert to CMYK, the behavior doesn't occur. I prefer working in RGB.

Is there any way to change this behavior? what is causing this?

See attached screenshots

Thanks!

[thelix]

Hi Shane.

Did you ever come up with answer for this issue? I am having the same problem with my spot channel seps since updating to PS2020 and it's driving me nuts trying to figure iout why it's happening. Any light you could shed on this for me would be greatly appreciated!

Thanks - Gary

[rob day]

I don‘t think I’m seeing the problem in CC2020—this post is 3 years old so I’m not sure the OP will respond. Do you have your Spot Channel’s Solidity set to 100%? If they are set to less than 100% I would expect to see a change in the spot color display when the RGB channels are hidden.

[thelix]

Thanks for responding. I know your post was old, but it was describing my
exact issue. The solidity of the spot channels doesn't make a difference
with the rgb channels on. What does solve the issue is converting to cmyk?

This issue just started happening last week, so either I have
inadvertently changed something, or a psd update has. Your right about the
OP responding. I'll make a new post and see if I get any responses.

--
*Gary Lick • *President • Midnight Impressions, Inc.

[Please do not post contact details in this forum]

[rob day]

What vesion of Photoshop? I’m not seeing it in the latest 21.2. Can you share a sample file?

[thelix]

I'm running 21.2 as well.

Here is a sample file. The 286 displays at about 50% with the rgb channels
turned on
on my machine.

--
*Gary Lick • *President • Midnight Impressions, Inc.

[Please do not post contact details in this forum]

[rob day]

Not seeing a link for the file. You can put it in your Creative Cloud Files folder, right click, and choose Share Link to get a URL

[thelix]

Sorry about that.....  here is a link   https://www.dropbox.com/s/ytp8t6emjbpu5d3/Test.psd?dl=0

[rob day]

In your sample file the background behind the RGB rectangle is transparent and the spot channel Solidity is set to 40%. If I turn the RGB Layer on and off the Spot color rectangle keeps its appearance:

If I set the RGB background to white with no transparency, the appearance of the spot channel at 40% Solidity is different overprinting white vs. transparency, but I think it has always worked that way:

If I set the Solidity to 100% the spot displays the same overprinting white or transparency:

[thelix]

Duh!.... you are right.
I thought I had the spot channel opacity set at 100%. Looks like I created
my own issue. That explains why it did not make any sense.

Thank you for straightening me out!

--
*Gary Lick • *President • Midnight Impressions, Inc.

*985 West Industrial St. / Azusa, CA / 91702626.334.3467 • fax
626.334-3467 gary@midnightimpressions.com
www.midnightimpressions.com
*