Black vs. registration

[mattinaakka]

Hi, I'm having some difficulties using images in a design with black background. I know that for print purposes I shouldn't use Registration, but use Black instead. If you see the screenshot I attached to this post, you see that the left PDF has Black background and the right PDF has Registration background.

Of course I desire the image to fade to the background like it does in the right PDF. I tried placing the image as both RGB and CMYK (coated fogra39) and exporting with High quality print (convert to destination: coated fogra39) but the image ends up darker than the background.

If I want the black in the photo to end up just like the background what would be the correct workflow? Thanks!

[rob day]

You can use the eyedropper tool to accurately sample colors from an image—it has to be an image—placed PDF or AI files sample the RGB proxy and not the actual color.

So, if you place an RGB image with a 0|0|0 black background, the eyedropper will sample RGB 0|0|0. If you use that as the ID background color it will export to the matching Coated Fogra39 black point (91|79|62|97) when Fogra is set as the destination.

If you place CMYK the same will happen, the eyedropper will sample the image’s CMYK separation color. If the InDesign black background has a lot of coverage, and the image background really is at absolute black, you might consider using a built CMYK rich black so you are not maxing out the Fogra total ink over a large area—something like 65|50|50|100. In that case there wouldn’t be an exact separation match, but the difference wouldn’t likely be discernible in the print.