False CMYK color in 1PMS file

[Tech]

Very odd, when a paper-white fill text box with transparency is flattened against a 1 PMS background... it creates what looks like a false-positive CMYK when the PDF files is preflighted. Of course, no extra color shows up in output preview. Has this happened to anyone else?

 

[leonardr]

Preflighted against what profile of what preflight application?

Can you post a sample?

 

[Tech]

Preflighted against what profile of what preflight application?

Can you post a sample?

Same InDesign layout export or print to postscript > distiller creates same result. PDF is then preflighted in Acrobat using our in-house settings and picks up 5 color plates in summary in each instance.

I'm guessing the is the usual transparency-and-spot-color-don't-mix problem. Our printer only accepts PDF 1.3-1.4. It looks this has something to do with flattening spot-text within paperwhite filled box overlaying a spot-color image background.

What is truly odd is that after preflight with show in snap on, it jumps to and identifies all spot-color text as CMYK.

I'll try posting a sample/screen when I have some downtime at work. I'll try export to v1.5 or higher and verify if this is simply a flattening issue.

Thanks for replying.

 

[Bret Hesler]

Just guessing, but Quark appears to define white as 100% RGB and Indesign as 0%CMYK.

Have you tried making the white box, 0% of the spot color?