See query.
It’s on the physics and chemistry of the thing. I’m sure the chip manufacturers have it down (to a science, heh) to extreme precision when costing, etc. using at least preliminary theory before going to testing.
From experience I know oil residue after cooking (which may or may not correlate with sense of “greasiness”) differs on absorbent and on “frying” temperature (untreated eggplant absorbs tons; frying food at too low temperatures makes more penetrate (although I’m not sure if that’s merely because it has more time–but duck confit, which is in bubbling fat for hours, has no significant penetration…). And low-low poaching temperature, eg fish filet in oil or lobster in butter, can leave a minute amount on some food.
So: thin potato substrate. Oil amount and temp unknown. And oil type, if it matters, which it might, certainly at higher temperatures/smoke points.
(Posted in attempt to distract myself with intellectual abstraction while feeling gross and stupid after eating a whole big bag of potato chips.)