That's not how it's done. You and only you can measure the height of your own frets. Every guitar is different.

But the height of your nut slots are determined by feel with strings on the guitar. Press down the string between the 2nd and 3rd frets, then set the nut slot so that the string just clears the first fret.

As I file the slots I measure the gap between the bottom of the string and the top of the first fret with a feeler gauge. I have learned over the years gaps that work for me (and a lot of others apparently), I slowly lower the slot until the tight string approaches that gap. Fwiw, starting with the first string, these will work pretty well but you might prefer something else - 0.014, 0.014, 0.015, 0.016, 0.017, 0.018. You will find those are less than most factory settings.

Based on ALL the advice in this thread, I decided to follow this example: for electric guitar: https://www.guitaranswerguy.com/guitar-action-good-string-height/
Low E: 0.3mm (0.012”)
High E: 0.15mm (0.006”)

so,

low E .30mm
A .27mm
D .24mm
G .21mm
B .18mm
high E .15mm

...done with: eye/ear/fingers and feeler gauge (won't be perfect!) LOL!

Not brave enough to do: "0.014, 0.014, 0.015, 0.016, 0.017, 0.018" - lol.

Anyway, I have a bit of fret buzz now! The 'relief' is OK (I.M.H.O). Can i Simply raise the individual saddles until the buzz is eliminated ?

The PRS specs. are:

Bass side E string height 1st fret: .60mm
Treble side E string height 1st fret: .40mm

Many Thanks!

I do four things.

Get the frets prefectly leveled and dressed, set the relief.

Draw a line with a half pencil laying on the first two frets on the face of the nut. That is a "zero fret" line and I want to approach it but not go beyond it.

As I file the slots I measure the gap between the bottom of the string and the top of the first fret with a feeler gauge. I have learned over the years gaps that work for me (and a lot of others apparently), I slowly lower the slot until the tight string approaches that gap. Fwiw, starting with the first string, these will work pretty well but you might prefer something else - 0.014, 0.014, 0.015, 0.016, 0.017, 0.018. You will find those are less than most factory settings.

As a final check I will do Barry's test - hold the string down at the third fret (it will also be touching the second) and check the gap at the first fret. I want some gap, as little as possible but still measureable or at least pingable.

can anyone confirm that this is an acceptable setup please?

cheers!

Oh poop!

I've just sat down for a quick practice and I've got a buzz on the 'G' string at the first fret!
After I cut the nut slots (AFTER), I decided to to tighten the truss rod to decrease the relief to 0.12mm (from 0.25mm) which required me to lift the saddles quite a bit! All seemed fine on the bench, but then 'playing' = BUZZ on 'G' @ 1st. fret.

Can I fix this somehow? "URGENT!"

The frets are near perfect level and dressed correctly.
The buzz on the 'G' string is happening when played 'open' (no hand fretting).
I realise I should have set the relief BEFORE cutting the nut slots, but it was a last minute impulsive decision to 'pull it back a bit', but it's backfired somewhat!
The truss was adjusted by roughly a quarter turn.
I suppose I could fill the slot with something and re-cut it, given it's a black graphtech (TUSQ) that is impregnated with lubricant.
Also, reverse the relief in tiny amounts until the buzz is gone? Then lower the saddles a bit to compensate?
Cheers to all helpers. many thanks!

Shim the nut.

Don't set the neck relief as a function of an incorrectly cut nut.

Set neck relief and cut the nut slots properly. If you went too far fill the slot or make a new nut and start over. Shimming a nut is a possibility too but on new guitars and high end guitars there is no substitute for a properly cut nut.

Filling is a long walk on a short pier for most here. The old CA and bone or nut material dust doesn't last very long and is not suitable for high-value commercial work in our view. We've invested in and have and use Dentist equipment with the activation light and light cured dental fillings in all shades so we can even match who J. Gilles described as Goober Goober with the Green Teeth (that's a song reference).

Light cured dental fillings are harder than the bone itself and last longer. But few have the technology to provide that so maybe try dust and CA and raise the slot and recut.

A string that buzzes open and the buzz goes away when fretted is almost always the nut slot is too low. This is another reason why nut slots should not be cut off the instrument nor should the half pencil line be used as a reference for slot depth but for removing excess top height only instead. Again I can cut a nut slot below the half pencil line and have it not be too low so that line is meaningless in the context of variable string gauges, stiffness and tension as they strings ark over and out of the nut slot face. More reason when nut slots are cut in real time on the guitar with strings on tuned to pitch and relief set.

the first fret action is probably too low

What should it be please?

. Fwiw, starting with the first string, these will work pretty well but you might prefer something else - 0.014, 0.014, 0.015, 0.016, 0.017, 0.018. You will find those are less than most factory settings.

As a final check I will do Barry's test - hold the string down at the third fret (it will also be touching the second) and check the gap at the first fret. I want some gap, as little as possible but still measureable or at least pingable.