Negative Gerber Layers

Does DK Red for 4 layer properly interpret Negative Gerber layers when they contain the line:
G04 #@! TF.FilePolarity,Negative*

When I uploaded Gerbers containing this line, the online Gerber previewer shows them as if the artwork is positive, despite the TF.FilePolarity.Negative line in the Gerber file.
Will the resulting boards be fabricated to interpret this negative/positive sense correctly?


As far as I know, the Gerber files containing the line “G04 #@! TF.FilePolarity,Negative*” are properly interpreted as Negative Gerber layers by Digikey’s Red for 4 layer PCB service. The line “TF.FilePolarity,Negative” specifies that the layer should be treated as a negative layer, meaning that areas with copper should be indicated as clear spaces in the Gerber file, and clear spaces should be indicated as areas with copper.

Whenever I find a vendors PCB checker/viewer does not show exactly what I expect, I do one of these things:

  1. Re-create my files using different options so that the PCB shows correctly in the checker/viewer
  2. Use a different vendor whose checker/viewer does show exactly what I expect
  3. Get a guarantee in writing from the vendor that the PCB will be correct even though the checker/viewer does not show exactly what I expect