Multiscale, Compound Radius, AND Fully Scalloped? Is All of That Necessary?

The fretboard on the Locust Plague sounds like a list of boutique-guitar excess: a 27–26.5-inch multiscale, a 12–20-inch compound radius, and full scalloping. Each feature addresses a different part of how the instrument works, though I will admit that part of the reason I combined them was technical curiosity. I had never seen anyone design all three as one continuous geometry, and I wanted to prove that I could do it properly.

The guitar was made for Karl Sanders of Nile, but he did not commission it or give me a specification sheet. I approached him because I had been a fan for years and respected both his music and the physical demands of playing technical death metal at that level. Some decisions came from conversations with him. Others came from studying his technique and the instruments he had used. I do not want to turn my interpretation into a quote from Karl, so where I describe what his playing seemed to need, that is exactly what it is: my interpretation as a builder and longtime listener.

Why Scallop It?

Scalloping made sense because of how much pitch movement Karl gets from his fretting hand. His solos often use wide vibrato, extreme bends, and overbent notes that have a wailing quality. The closest comparison I can make is the broad pitch inflection heard in instruments such as the sitar, even though the mechanics are different. Karl has also spoken publicly about the influence of Ritchie Blackmore and especially Uli Jon Roth on his interest in scalloped fretboards.

On a conventional fretboard, the fingertip eventually presses against the wood. With a scalloped board, the string remains suspended between the frets, allowing the player to continue affecting pitch through pressure and lateral movement. Contact with the fret can feel immediate, and the player has more room to manipulate bends and vibrato. The same sensitivity also makes the guitar less forgiving. An uncontrolled grip can easily pull notes sharp.

Karl’s setup makes this even more interesting. By my recollection, his action was around 5/32 inch, which is very high for a modern electric guitar. He still plays extremely fast and aggressively. The scallops were never intended to turn the guitar into a low-action shred machine. They supported the pitch control and expression he already used while preserving the setup he preferred.

Designing the Neck Around the Scallops

Most scalloped fretboards begin as conventional boards and are modified later. I wanted the neck designed around the missing material from the start.

Instead of beginning with a 0.250-inch fretboard, I made the ebony 0.300 inch thick. That extra 0.050 inch did not make the finished neck any thicker. I removed the same amount from the neck portion beneath the fretboard, preserving the original overall neck thickness and profile. I was redistributing material rather than adding bulk, placing more of the total thickness in the fretboard where the scalloping would remove it.

The scallops are roughly 0.100 inch deep, leaving about 0.200 inch of solid ebony beneath them. A tenth of an inch is not a shallow decorative cut. The conservative part of the design is the additional starting thickness and the amount of ebony left under the deepest point.

The fretboard contributes to the stiffness of the neck once it is glued to the neck blank, and scalloping removes material from the outside of that structure. This guitar also has a long neck, with a 27-inch bass-side scale and a high body joint, so I wanted to preserve every useful bit of stiffness. The thicker board worked together with the laminated neck and graphite reinforcement.

The result did exactly what I hoped. Karl took the guitar on the road in 2025 and later told me that it was one of the most stable guitars he had toured with, possibly the most stable. That confirmed the basic idea. When a fretboard is going to be fully scalloped, the neck should be designed for it instead of treating the scalloping as an operation performed on an otherwise conventional neck.

Why Use a Compound Radius Too?

Scalloping and radius affect different parts of the fretboard. The scallops change what the fingertip contacts between the frets. The radius determines the transverse shape of the board and the fret tops.

I use a 12–20-inch compound radius because I think it is the best general geometry for an electric guitar. The lower end is rounder, which suits the curved hand position used for chords and lower-position playing. As the hand moves up the neck, the thumb often moves toward a more perpendicular, almost classical position, and the flatter surface becomes increasingly appropriate.

The flatter upper register also gives a bent string more clearance over the following frets. On a tightly radiused board, a string moves toward the highest part of that curve as it is bent, increasing the chance that it will contact another fret and choke. Flattening the board toward the upper register allows lower action and wider bends without fretting out.

Karl’s action was high, so the compound radius was not there only to chase the lowest possible setup. It still suited his hand position and bending style. The geometry gives the setup more room to work without dictating how the guitar must be adjusted.

The scallops were created from that compound surface in Rhino. I began with a complete unscalloped fretboard, generated the changing radius, and laid out the multiscale fret positions precisely. The scallops were then derived from that geometry.

They are not identical scoops copied down the board. Each one follows the local radius, the changing fret spacing, and the angle of the surrounding frets. When the finished board is rotated under a light, the changing surfaces become obvious. The highlights move differently through each scallop as the radius and spacing change. It is a complex geometric shape, and seeing it in person is extremely satisfying.

Why Add Multiscale?

The multiscale is mild: 27 inches on the bass side and 26.5 inches on the treble. Karl plays in very low tunings but uses extremely light treble strings. The lower strings benefit from a little additional length, while the upper strings do not need all the tension that would come from making the entire guitar 27 inches.

For the same string at the same pitch, moving from 26.5 to 27 inches raises tension by roughly 3.8 percent. That is a modest change, which was the point. I was not interested in an exaggerated fan that would force Karl to alter familiar shapes or relearn his technique. The bass side received a little more length, the treble side remained slightly more pliable, and the guitar stayed close to the long-scale instruments he already knew.

Multiscale also gives each string a more suitable speaking length before the final intonation compensation is established at the bridge. It helps manage the different requirements of the low and high strings rather than forcing the entire set onto one compromise scale.

Part of my reason for adding it was simply that I wanted to solve the geometry. I had never seen a fully scalloped, compound-radius, multiscale fretboard, and I wanted to know whether I could make one. I enjoy difficult design problems, and sometimes I make something because I want to prove that I can. The technical exercise still had to produce a useful instrument, especially when that instrument was going to a touring player.

The three features have separate jobs. Multiscale distributes speaking length and tension across the string set. Compound radius changes the curvature of the board through different playing positions. Scalloping changes the relationship between the fingertip, string, fret, and fretboard.

Compound radius and multiscale together are, in my opinion, about as good as an electric-guitar fretboard gets. Scalloping is the matter of taste. Some players would hate the sensitivity, and anyone with a heavy, uncontrolled fretting hand might struggle to play it in tune. It is not appropriate for everyone, but it made sense for Karl.

Designing the Rest of the Guitar Around Karl

Almost all of the Locust Plague came from observing Karl, his playing, and the instruments he had used, especially his KXK guitars. Some of those instruments are visually more extreme than I would normally build, but they showed me the physical and musical environment this guitar needed to work in.

One body feature came directly from talking with him: the large sloped bevel across the bass side. That entire side falls away beneath the arm and wrist. Karl had mentioned guitars that put his wrist in an uncomfortable position, and I wanted this V to remain comfortable while sitting. The bevel makes a surprisingly large difference. You can sit with the guitar for hours without the body constantly reminding you that it is a V.

I also keep the string plane and bridge hardware as close to the body as I reasonably can. Many of my favorite guitars growing up had low-mounted Floyd Roses, and that shaped how I think about hardware. I want the bridge to disappear under the picking hand rather than make the player work around it.

Those decisions may have mattered more to Karl than the fretboard geometry. The feedback I remember most clearly was that the guitar stayed in tune, played in tune, felt light, and remained stable on the road. I am not sure the multiscale was the most important part of the instrument to him. The light weight, tuning stability, and overall usefulness seem to have mattered more.

When he later brought the guitar to the school, the case handle and the back of the neck had clearly been handled a great deal. Plastic and finished surfaces gradually become polished where human hands repeatedly touch them. It was obvious that the guitar had been carried and played.

That made me happy because I wanted the instrument to be useful. I want to be in service to the creation of the music, and that means making something the player actually reaches for rather than an object admired mainly for its specification sheet.

Building the Locust Plague did not change my thinking about scalloped fretboards. It confirmed that I should build them this way: a thicker board, controlled scallop depth, reinforcement planned from the beginning, and the entire surface designed as one system. The guitar worked well enough that I would not change anything about it. In fact, I am planning to make one for myself.