View Full Version : Spot color behind a bitmap with transparency

05-04-2012, 08:58 PM
Equipment: C7000, IC-306
Client software: Adobe InDesign CS5, MacOS 10.5.8

As you know, Spot-On Color and Spot-On with Substitute Color both work only on vector art, not bitmaps. But in my customer's InDesign document, inside of a horizontal rectangle with a spot-color fill, is a portrait photo with the background around the subject's silhouette made transparent.

When I adjust the color using Spot-On (using Substitute Color -- see my other thread), the change is reflected in the output -- but not behind the photo.

Troubleshooting, I exported the original, non-color-adjusted job to a PDF file using SeeQuence Preview, and in Acrobat, used the eyedropper tool in Pitstop to measure the rectangle's color fill both alongside the photo and over the transparent part of the photo. The result: a couple of color components changed very slightly -- by about 0.12%, well within the latitude of Spot-On with Substitute Color. So when I printed the job with Substitute Color on, the color behind the photo should have changed too, right?

Rinse and repeat with Composite Overprint turned on. Still, the color behind the transparency remained unfazed.

Repeat by importing the PDF exported from SeeQuence Preview (see above), with APPE turned on. Still, the color behind the transparency did not shift with Substitute Color turned on.

Repeat again by opening this PDF and going File > Print to flatten it to PostScript. Same result.

In summary, I have not been able to get the color behind the transparency to react to Spot-On with Substitute Color.

Is this the expected behavior, or is there something else I can do to try and make this work?

What a day! Thanks for any help.


05-07-2012, 08:20 PM
Closing the loop: Solved. Not sure of all my facts, but after having the customer change the background color from process to spot, Composite Overprint seemed to work. The background color is now consistent across the board, even behind the transparency in the bitmap.

I should go back and re-test Composite Overprint again with the background color set as a process color, but I don't want to look success in the mouth, if you know what I mean.