I was able to apply the gold graphic to the bottle using a Corona decal, but am having difficulty getting the white background square behind it. My plan was to use another Corona decal for the background, hoping to remove the displacement effect through the decal properties. Unfortunately, I haven't been able to make that work. Is there a way to do this with corona decals, or is there a another, easier way to do this? I thought this would be a relatively simple thing to do, but all of my efforts have not brought about the intended results. Any help would be appreciated.
If i understand correctly what you want, this should be possible to do with decals. Make sure second decal (the one with white square) has displacement enabled and
add to base disabled. That way its displacement will override bottle's displacement and you should have knurling free area where you want.
Like always there are other methods to achieve what you want that does not require usage of decals, but if decals are working for you, i see no reason not to use them.