Katalox — Density, Movement, Workability & Cost

A guitar fingerboard needs to be dense, dark, and dimensionally stable, and true ebony delivers all three at a price that puts it out of reach for a lot of builds — katalox (Swartzia cubensis) delivers a genuinely close approximation of the same look and feel at roughly a quarter of gaboon ebony's price, which is exactly why it's become the default budget-ebony substitute in guitar building.

Nearly ebony, at a fraction of the cost

At 71.6 lb/ft³ and 3,660 lbf on the Janka scale, katalox is extremely dense and hard, approaching true ebony's numbers closely enough that most players can't distinguish a katalox fingerboard from a genuine ebony one by feel alone. The heartwood runs from deep purple-brown to near black, though a wide band of pale sapwood typically surrounds it — a buyer pays for the whole log, sapwood included, so asking specifically about heartwood yield matters when ordering.

Movement in small, instrument-scale pieces

Radial shrinkage of 3.9% against a tangential figure of 7.6% gives a 1.9 ratio, just under this site's movement-prone threshold — high enough that a glued-on fingerboard genuinely needs the neck's own seasonal movement considered alongside its own. A 4"-wide blank drying from 9% down to 6% gives up about 0.03" (0.8mm) across the width; the wood movement calculator covers other widths. A 20"-long fingerboard blank at that width, milled 1/2" thick, weighs about 1.7 lb at katalox's very high density — the wood weight calculator covers other blank sizes.

Gluing an oily, dense surface, and a finish that needs little

Some natural oiliness means a degrease before gluing is a sensible precaution, and epoxy is the more reliable structural adhesive over PVA. It cuts cleanly with carbide, turns beautifully, and takes a screw thread — a genuinely metal-like working quality shared with several of the densest species on this site. It burnishes under a scraper to a natural gloss that needs little additional finish.

Durability, cost, and where it competes directly with true ebony

Katalox is very durable, with strong resistance to both termites and marine borers. At roughly $24 per board foot it sits meaningfully below gaboon ebony's roughly $130 and macassar ebony's roughly $110, which is the entire basis of its appeal — a builder who wants ebony's look and feel without ebony's price finds katalox is close enough on both counts to make the substitution genuinely credible rather than a compromise. Guitar fingerboards, turnery, knife scales, inlay, and flooring round out its markets.

The honest comparison, not just the marketing pitch

Katalox doesn't quite match true ebony's absolute density or its uniform jet-black colour — the sapwood band and the somewhat more variable heartwood tone are real, visible differences a careful buyer will notice. What it does deliver is genuinely comparable hardness, comparable stability, and a dramatically lower price, which is exactly the tradeoff that has made it the standard "ebony substitute" rather than a marketing fiction.

What people actually ask about katalox

Do experienced luthiers, as opposed to players, notice a working difference between katalox and true ebony at the bench? Some report katalox as slightly less consistent to fret-slot and radius than dense, uniform gaboon ebony, since the wider sapwood band and more variable heartwood density can behave a touch differently across a single fingerboard blank — a subtlety unlikely to affect a finished instrument's playability but worth knowing before committing to katalox for a highest-tier build.

Why is katalox so much cheaper than gaboon or macassar ebony despite similar density? Broader natural distribution and less demand pressure from the specific luxury and collector markets that drive up true ebony pricing both keep katalox considerably more affordable, even though its raw physical properties are genuinely comparable.

Is the pale sapwood on a katalox board usable for anything? It's usable for non-structural, less demanding applications, but it lacks the heartwood's density, colour, and durability — most buyers specifically request maximum heartwood content for fingerboard or accent work, where the sapwood offers little of the value the species is purchased for.

Katalox is missing from the USDA Forest Products Laboratory's Table 4-4 entirely, so every figure above — density, Janka hardness, shrinkage — comes from The Wood Database's own 12%-moisture-content testing instead.