Official Luthiers Forum!

Saw an excellent picture of a very tough thing to photograph that I've tried and failed and never got a good pic of. This photo is a Stew Mac photo and it illustrates the "line" that in great fret work we want to achieve AND maintain.

This is the flat that results from leveling the frets and once we achieve our "level set" and in our case also mill in relief in varying degrees on the bass and treble side these lines are achieved by refining the fret crown with files. Be it a modern, diamond crowning file or old school three corner the end result goal is the same, we want to see this line preserved AND refined to about the size pictured for the fret with the narrowest line.

It's common to break the line a bit here and there and that's pretty OK but we try not to and with practice you will get better at achieving this line and maintaining it too.

Additionally there is another concept that is well displayed in this photo and that is a more crowned fret, the one with the narrow line also has more gradually crowned sides and not a "school bus roof" like the one with the fat line.

I had a discussion here several years ago with someone who could not seem to understand what I spoke of when I referenced "the line" and this is one of the most basic and critical concepts in good fretting regardless of your method if it's different from what Dave and I do. The line must be achieved, maintained and refined or you lose your level set and all the hard work achieving same.

Now why the narrow line? If you look at the fret with the lousy, fat line and you were to draw a picture of a fretted string the string would break on the fretted side of the fat line a goodly amount. This is also a goodly amount off center of the fret crown and will result in poor intonation of that fretted note and typically a sharp note.

If you have ever played a guitar even a brand new one that many notes seem pulled sharp upon fretting it's often two things separately or in combination. High nut slots cause notes to be pulled WAY sharp if the nut slots are very high and somewhat sharp for somewhat high. And poorly crowned frets with school bus roofs also do the same thing.

I've been collecting guitars filling my studio for my retirement, getting the band back together LOL so I have bought a goodly amount of brand new guitars in the last three years. Two out of three Gibsons that I bought both needed to spend more time on the PLEK with more passes of the cutting head because they both had school bus roof frets. The custom shop Gibson appears to have spent more time on the PLEK and plays more in tune out of the gate. Of course I cut the nut slots down because Gibson and most everyone else don't and I fret dressed my 2019 Les Paul and SG immediately after receiving them from Sweetwater because I cannot stand to play a guitar with a poor fret plane and set-up. The custom shop 335 I bought I did not need to do a fret dress but it did need set-up.

So this pic that I just saw as Stew Mac spammed me of Facebook made me think that this would be a great discussion here the line and why we refine the crowns on frets to NOT be school bus roof shaped.

For some folks who have better control of their fretting hand they can play tall, poorly crowned frets with a light touch and minimize the intonation issues. I play so many different guitars in a day now that I have no ability to get used to any one of them.

Anyway this may seem like nit picking to some but that's what great Lutherie set-up work is, nit picking, the details and it's all for a desired result to have a guitar that nearly plays itself and encourages the player to be their very best.

PS: We don't like the Z files and instead use the original Stew Mac diamond files and always have. I also use a three corner to refine the fret sides and it's quick and easy and is only three strokes usually for me.