Here is the telltale difference between a
Grease Fill and and over polished die.
SIZE matters her, note how thin the devices appear, this is effects of polishing. The die face has been removed creating shallow cavities. Because of the angled design, these devices are cut thin at the ""peak" and larger at the "valley" which is the field level or die face.(mirror image remember). A
Grease Fill, plugs the thin "peak" areas which then results in THICKER (wider) devices.
