Reply To: Spot Varnish—After the fact

This is hard. Perhaps you could edit the object style to have a spot color fill (assuming the frames have no fill already). But then you’d need to delete all the images (there’s a script to do that) before printing that plate… hm…

If all the images are on their own layer, you could dupe the layer on each spread, then hide the one with the real images, run a script to delete the images on the dupes and fill with spot… would have to be done one each spread, though.