Colors not converting properly from AI to Photoshop

OK, I did what I should have done a long time ago: I did some testing.

My theory seems to hold. Here's a bit from an sRGB .ai file, and the central gray area was defined as RGB vs grayscale. They appear identical in Ai.

When defined as K, and exported to PDF, it opens in Photoshop like this. First with Photoshop's working gray as dot gain 20%:

So that's a bit lighter. With working gray gamma 2.2, it looks like this:

Closer, but still not a perfect match.

So then I tried again, but this time, the gray area is defined as RGB. And now they all display identically in Photoshop, and identical to the .ai original:

My immediate suspicion here is that Illustrator doesn't color manage grayscale at all, but I'd need to do more testing to get to the bottom of that. In any case - always define swatches as RGB or CMYK, and you'll be fine (but stay in the main document color mode). Then color management works and does its thing. Avoid grayscale (K) values.

Edit - written before I saw Danny's post. Taken together they should probably cover most scenarios.

Just a few general tips for safely working with grayscale images.

For offset print, convert using the "working gray - black ink" option (see screenshot above). Paste the result into the K channel in a new CMYK file, so that it prints on the black plate only. This will now for all intents and purposes be a standard CMYK file that should be handled correctly everywhere.

For screen/web, I usually just convert to sRGB and think no more of it. But if you set your working gray to gamma 2.2, you should be safe in most circumstances and see the image correctly.

Desktop printers always expect RGB data, so the same here, just convert. If you need to print with black/gray inks only, there's usually a setting in the printer driver to take care of that.

My, this is getting confusing. I've suggested that the other thread is locked, and we continue the discussion here.

Parallel posting in both threads:

And as far as I can make out, the dark gray ellipses are defined as grayscale:

Grayscale is a can of worms. It will render according to working gray in Photoshop, so that's the least of the problems.

But Illustrator and InDesign have pretty poor grayscale support. In a PDF it should export as CMYK, 0-0-0-K, but with the tone response curve of that particular CMYK profile. This is not the same as a default working gray in Photoshop. AFAIK none of the dot gain profiles correspond exactly to any given CMYK profile.

So cp is right, this particular problem should go away with a little more discipline and consistency in setting up the document.

But aside from that I agree that Ai's and Id's grayscale support leaves a lot to be desired. Photoshop is doing it right.

In the ai file there appears to be a mixture of RGB and CMYK colors.

Hex values mean nothing. Hex is a leftover from before color management was invented. In the same way, "RGB" means nothing, that's just a generic color model.

You need to get specific with icc profiles. sRGB? Adobe RGB? ProPhoto RGB? They all produce different colors with the same numbers, and that includes hex numbers. Make sure all apps are set up to embed the profile when saving, and to preserve that embedded profile when opening. They will be at default settings.

To make things simple for a start, use Bridge to synchronize color settings, and pick one of the presets.

Grayscale is a special case that comes with its own set of grayscale icc profiles. So you should also make sure that Photoshop isn't opening your RGB file as grayscale.

Moving to Photoshop.

Regards

Rajashree