Not sure why kicad didn’t just output an EMPTY file for FSilkS, but used %LPC*% to blank out some passages. Very odd.
Gerber viewers don’t have an issue, but the FAB sent me hundreds of white boards
Difference between FMask and FSilkS
Just for reference https://bugs.launchpad.net/kicad/+bug/1626700.
It’s not a bug in kicad.
Seems the fab misinterpreted %LPC*% (used to remove silkscreen potentially overlapping open space in the mask layer). The %LPC*% block is triggered by selecting “subtract soldermask from silkscreen”. Up until now I was under the impression that the subtraction was done internally and not in the gerber output itself.
Yes, they could make that operational detail a little clearer in the wording/hints.