For many years - from around 1980 until a few years ago - there was an unofficial rule in the US acid scene that paper be dosed no higher than 100mcg/hit. Due to varying crystal purity, deliberately weaker laying, and degradation of product over time most hits were under 100mg - often well under - but no one saw hits dosed higher outside of specialty 'family' stashes.
That changed some years ago due to the re-writing of the carrier weight sentencing laws and the influx of LSD from outside the US. Now there are many paper doses of 150-250mcg, though the majority of what is available is much weaker.
Paper hit size, drop size, microdot or barrel size has nothing to do with dose.
So bottom line - there was a sort of standard for twenty + years, but no more.....