Try Export Vector PDF:
1. Go to menu: File | Export | Postscript PDF...
2. Verify Format Type is "PDF"
3. Press button Next, and proceed with PDF Layer selection.
Note: It is here that you can select whether you want to have certain layers as Dark or Clear.
Here's a quick tutorial movie where I export a plane layer as negative (in the PDF), let me know if that helps:
https://numericalsoftware-update.s3.amazonaws.com/tutorials/2016-07-07_13-01-55-pdf-vector-export-negative.mp4
Simon Garrison
Try Export Vector PDF:
1. Go to menu: File | Export | Postscript PDF...
2. Verify Format Type is "PDF"
3. Press button Next, and proceed with PDF Layer selection.
Note: It is here that you can select whether you want to have certain layers as Dark or Clear.
Here's a quick tutorial movie where I export a plane layer as negative (in the PDF), let me know if that helps:
https://numericalsoftware-update.s3.amazonaws.com/tutorials/2016-07-07_13-01-55-pdf-vector-export-negative.mp4