Why do some boutique or custom guitars have a "Zero Fret" and what makes this a big deal? And as a follow up, why don't all guitars have one of these?

It is not a boutique or custom deal.... when I was first learning to play, many of the cheaper guitars had them and I at first attached that idea to a lesser quality instrument. Then as time went by, I noticed that it was just a choice, not a quality judgement.

One thing that I like about the zero fret... fretted notes and open notes sound the same.

It's another way to dictate the string-height at the 1st fret, as the "zero"-fret makes that the same as compared to another fret with the strings barred at the preceding fret. And with a zero-fret, the nut acts more as a string spacing guide and less, if at all, as setting the string height at that end. And, as Bill states, it gives open strings about the same sound as fretted ones.

On a standard design guitar, the nut is the beginning point for the scale-length of the strings; with a zero-fret, the zero-fret is that beginning point, and the nut is located behind that point.

Both zero-fret and standard nut/1st-fret designs need to be crafted and set-up with precision, although the nut behind a zero-fret is a little less critical in some respects.

Note that a lot of vintage Gretsches came with zero frets, just one example of many.

A lot of gypsy jazz guitars come with a zero fret. Personally, I think the characteristic sound of open strings at the nut sound beautiful and are a good contrast to fretted notes if used correctly. IE: we dont hit open strings when playing straight ahead jazz because of the oddball tonal contrast.

Seems then, this would be desirable to have as it would make setting up the string height more accurate and take the nut height out of the picture.

Dave Wendler? Boggs? I'd love to hear your thoughts on the matter of zero-frets...

Only played on an acoustic with a zero fret made in italy a few years ago and it did feel like it was easier to play for some reason...but that's about it...not too many major brand guitar makers use them so they are not in demand on standard models...almost all custom guitar makers leave them off as well....

It seems to me like you could get away with a lower quality, less well slotted nut with a zero fret. It makes me wonder if manufacturing costs are saved with the zero fret setup.

O'Shite and Guitar Slinger are correct.During the late-sixties onslaught of cheap offshore guitars sparked by the British Invasion (which had, in turn, been sparked by the success of the Beatles)the zero-fret reached its apex. Because nut shaping was less critical with a zero-fret design, the Z-fret became associated with these lesser-quality imported instruments, causing Gretsch and other US manufacturers to abandon it.

Welcome aboard Mojo Bone....

This is a left turn from the OP but why do some guitars have fret markers at the first fret ?

For looks is the only reason I can come up with...the fret marker at the first fret makes no sense at all...if it did there would be one on the 13th fret as well...IMHO

I had an unlined fretless bass with a side dot at the first fret position - made a lot of sense in that context, but as for standard? Nope.

G.

Yeah, welcome, Mojo Bone!

And, yeah, as far as I know, for the most part whether to mark or not mark at the 1st-fret seems to be a matter of aesthetics.