Spot Colors and Transparency Flattening in InDesign CS3
I was preparing a demo on transparency flattening and to my great surprise there are some very interesting news in InDesign CS3. What I wanted to show was the “White Box Effect” which Steve Werner described very well in this post. The problem happens when transparency is flattened over an object with a Spot Color. By now we all know that if you turn Overprint Preview on in Acrobat the problem disappears on screen. But, to this day, there are still problems with printing such effects in certain workflows (mainly those that have an internal preflight system and which automatically turn overprinting off for these “transparent” elements).
Well, in InDesign CS3, the engineers came up with a very cool idea! The problem: some preflight systems consider the white box in overprint an error… and turn overprinting off on that specific element; causing the horrid white box effect on output. Solution: overprint the spot color instead! Splendiferous!
Figure A. How transparency effects on Spot Colors used to look in Acrobat with Overprinting Preview off.
Figure B. How transparency effects on Spot Colors used to look in Acrobat with Overprinting Preview on.
Figure C. How transparency effects on Spot Colors now looks like in Acrobat with Overprinting Preview off.
Well, it looks pretty much like there is no transparency effect at all! Wait a minute let’s turn Overprinting Preview on, and this is what we’ll get:
Pfew! Here’s the shadow.
So what is so fantastic about that solution? Well, white is not the color that overprints anymore; thus reducing preflight errors. It’s the spot color that is overprinting. Problem solved. Next?