What is Ebonite?

Hint: It’s not plastic!

Shop Notes Blog

Ebonite is a natural hard rubber and its name comes from the fact that it was invented as a substitute for Ebony the African hardwood. The potential of this food-safe material was discovered by flute makers not long after it was patented in the 1800s (and it should be noted that early ebonite recipes were probably *not *food safe). It is often used for saxophone and clarinet mouthpieces and because it is durable and not affected by moisture it has many advantages for woodwind instruments and has tone reminiscent of dense rosewoods.

It is significantly more costly than wood as a material. The beautifully colored types of ebonite costs about five times as much as African blackwood, a highly favored tonewood.

Richard Rockstro (1826-1906, the famous pupil of Richard Carte) endorsed the material in the following comments:

  1. Firstly, then in the matter of endurance it may be pronounced perfect for it is practicably indestructible.

  2. Secondly, as it is absolutely non-absorbent of moisture no change in the dimensions of the tube ever occurs, and a metal head-ling is unnecessary.

  3. Thirdly, an ebonite flute invariably improves by judicious use.

  4. Fourthly, this substance possesses just the amount of rigidity necessary for the retention of the enclosed air-column in its proper shape and dimensions, while its own vibrations sympathize so readily with those of the air within, that the sound is produced with as little expenditure of the breath as on a metal flute.

  5. Fifthly, this material is so bad a conductor of heat that ebonite flutes are far less affected than any others, in their pitch, by alteration of temperature.

  6. Sixthly, its appearance excels that of the finest ebony, and it generally retains its original lustre with very little attention, though sometimes it loses its extreme blackness.

Ebonite is a pleasure to use. It is beautiful, stable and sounds amazing. Is it a better choice than wood? I would say that sometimes it is, though I would differ with Rockstro in describing it as “practically indestructible”. Ebonite is pretty robust, but if dropped on a hard surface or subjected to trauma it can certainly chip or break, so it is much like wood in that respect. The following quote is from an excellent article written by clarinet maker Tom Ridenour (The Grenadilla Myth). He refers to ebonite as “hard rubber”, which is perfectly accurate. Natural hard rubber is what it is, and the term “ebonite” is more like a brand name that has become a convenient way to refer to it.

“Hard Rubber vs Grenadilla

In my own clarinet design experience I have had the rare opportunity to design clarinets in Grenadilla wood, Rosewood and Hard Rubber. It has been an eye opening, almost shocking experience. What I have found to be consistently true is when a well-made hard rubber clarinet is compared to a Grenadilla wood clarinet sharing the same acoustical design, the hard rubber turns out to be the unequivocal better in every respect: tone, tuning, response, sweeter high tones, stability and consistency in manufacture.

Hard Rubber is Natural

The fact is, too many people operate on the unexamined assumption that hard rubber us just like plastic. But the truth is that hard rubber is not at all like the plastics used for clarinet building. It is not accurate to equate high grade, natural hard rubber clarinets with synthetic, plastic clarinets.


For one thing, hard rubber is not synthetic at all, but just as natural as any piece of wood in any forest. Hard rubber comes from the very essence of the tree, being its’ life blood. Besides being natural, it is superior to plastics in every possible respect. Musically speaking, pure, natural hard rubber clarinets possess many critical playing and tonal qualities that are almost identical to those of Honduran Rosewood; more so than any other material presently used for clarinet making, including Grenadilla wood!

Comparing Grenadilla and hard rubber clarinets from a pragmatic, logistical standpoint, hard rubber clarinets are consistently more stable, more uniform from clarinet to clarinet, take and hold much more precise and uniform bore dimensions, and are virtually crack-free. On the acoustical/aesthetic/performance side, well-made, well-designed, high quality hard rubber clarinets have quicker response, more even blowing resistance, better, more stable tuning, a darker, sweeter tone and are coloristically much more stable throughout the full pitch and dynamic range of the clarinet. In short, hard rubber clarinets give you the best of both worlds, satisfying the logistical needs of the manufacturer and the artistic needs of the clarinetist.”

This was the article that inspired me to try ebonite in the first place, and my experiences so far coincide exactly with the observations made by Mr. Ridenour. Ebonite is an amazing material for woodwinds.

I also have other motivations for using it. As a flute maker, I have often in the past used various tropical hardwoods, but as time has gone on I’ve become a bit uncomfortable in not knowing if they are being responsibly harvested. Additionally, many of these woods require extended amounts of time to season and stabilize for use, which can be burdensome and require long-term stockpiling and organization of timbers. This is not an easy thing when a maker has a wide variety of flute types in their catalog. Fortunately, some of the more popular flute timbers such as African Blackwood, Mopane or Boxwood are not from the rainforests and have a much better record of sustainable harvest and management, though they do still require a lot of seasoning and stabilizing (and I do use some of these woods upon occasion). But ebonite has proven to be a wonderful substitute for all kinds of woods that I had used in the past. It is beautiful and has such a wide variety of colors and appearances that it is a delight to the eyes. And coupled with its many virtues as a material for woodwinds, it does a wonderful job of rounding out the options available to players.

Ebonite is an all natural blend of rubber sap, linseed oil and sulfur and is a very sustainable alternative to wood.

So I will be using up all of my stock of tropical hardwoods over the course of the next year and not replenishing them. This stock will be replaced by a variety of high quality, non-threatened domestic woods, and of course Ebonite!

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Published Monday, August 6, 2018