Tough Choices: Companies are Exploring Sustainable Alternatives to Tropical Hardwoods for Stringed Instruments

By Brian Wise | From the September-October 2020 issue of Strings magazine

Music may have charms to soothe a savage breast, soften rocks, and “bend a knotted oak,” according to the poet William Congreve. But as any instrument maker will tell you, those charms don’t apply to ebony trees, not where a violin, viola, or cello is concerned.

The hard, dense, main component of fingerboards and tailpieces, the type of ebony most commonly used for stringed instruments was once found throughout Africa’s Congo Basin and Madagascar. But in the past three generations more than half of the world’s ebony has been harvested, and four species of the wood are classified as endangered, one critically. Illegal logging has driven the destruction of native animal habitats, a rise in greenhouse gas emissions, and a surge in violence and corruption.

Swiss Wood Solutions Sonowood

A handful of companies have emerged with alternatives to ebony and other disappearing tropical hardwoods. Among them is Swiss Wood Solutions (SWS), the maker of Sonowood. The small company, based near Zurich, sources local woods including spruce, maple, and walnut from sustainably raised forests in Switzerland. These are pre-treated in a liquid bath to soften the wood fibers and are then compressed, resulting in a timber product that is “harder and denser” than ebony and “much more resistant to scratches,” says Munish Chanana, the company’s deputy CEO and head of research and development.

Early responses suggest that Sonowood also has sound characteristics similar to ebony. Kathy Reilly is the co-owner of Vermont Violins, in Burlington, Vermont, which in January began featuring the material on its in-house line of V. Richelieu violins and violas. A trained botanist and self-described environmentalist, she was drawn to the company’s message.

“The nice thing about the wood is it feels like wood,” she said. “I know that players are really interested in sound quality and they’re really interested in feel.” But acoustics and feel are only part of the picture. Opinions about the visual aesthetics of Sonowood are more varied, especially when it comes to fingerboards. “The surprising response we got was: ‘Well, it’s not black,’” Reilly said. “We said, ‘Who cares? Are we really going to choose plastic because it’s black?’ It was really distressing, actually. The makers are concerned that the players aren’t going to choose it.”

A violin using Sonowood components

By plastic, Reilly refers to Corene, another ebony alternative developed by another Swiss firm, Neo-Ebène. Its core ingredient is a synthetic polymer that shares properties with Bakelite, the world’s first synthetic plastic. Though some makers say that the look and feel of Corene is closer to true ebony, it is not naturally sourced or biodegradable.


Chanana believes that color is not such an issue. He notes that Sonowood can be treated with natural dyes to give it a black finish. Walnut is naturally dark and becomes even more so after the densification process. “Instrument makers give a high value to sound in the end,” he said. “For the sound quality of the instrument, they usually choose spruce, which has a golden color. People who go more for looks will take walnut.”

Carving a Partones ebony-alternative frog
Carving a Partones ebony-alternative frog

Swiss Wood Solutions was founded in 2016 as a spin-off from the Swiss Federal Institute of Technology (ETH Zurich) and the Swiss Federal Laboratories for Materials Science and Technology (Empa). “We were approached by violin makers three or four years ago asking for alternative, wood-based solutions,” explained Chanana, a chemist by training. “They didn’t want to have any plastic or plastic-composite fingerboards. They asked if it would be possible to grow ebony here at this latitude or if we have a European wood that is as hard as ebony.”

“A maple tree would take maybe 30 years to grow triple its size whereas an ebony tree needs 200 years to grow to an equivalent size.”

Ebony does not grow in Europe, and its closest equivalent, European boxwood, has been ravaged by boxwood blight and an invasive insect. Chanana says that Sonowood brings other ecological benefits. Unlike tropical hardwoods, the European woods don’t create large carbon footprints through shipping (a buyer can trace a tree’s origin through a GPS tracker). The wood is also fast growing, making it more eco-friendly. “A maple tree would take maybe 30 years to grow triple its size whereas an ebony tree needs 200 years to grow to an equivalent size,” Chanana noted.

The oldest ebony trees contain the largest proportion of jet-black wood, the kind that is prized for string fingerboards, piano keys, cabinets, and furniture. However, the tree’s exterior does not readily reveal its contents (the younger wood contains blonde streaks). Therefore, much of what loggers cut down is abandoned on the forest floor. “They cut 20 trees and only one is taken from the forest,” said Chanana. “If those forests would be sustainably managed, you would leave those younger trees standing so they could grow, and then cut them when the time is right.”

Sonowood scroll

Joseph Curtin, a prominent luthier in Ann Arbor, Michigan, has used the compressed spruce species of Sonowood in place of carbon fiber to reinforce necks. “The Sonowood products solve a number of problems apart from sustainability,” Curtin writes in an e-mail. “They seem to be more stable in the face of changing humidity than untreated wood, more wear resistant, less damped acoustically, very stiff, and as dense as wood can be.”

The high density, Curtin adds, is a mixed blessing. “It adds stiffness, but parts made with it become relatively heavy.” Curtin says that design tweaks can remedy this. For an Ultralight viola fingerboard, for example, he used “a spruce core, Sonowood on the sides, and Sonowood in veneer form on the top and bottom.”


A Sustainable Alternative from Lapland

Newer to the field is Partones, a Finnish startup founded in 2018 by Armin Seebass, a bow maker with a background in forestry, and Kristiina Aatsinki, who manages sales and administration. The team is developing a line of sustainably sourced wood composites, aimed at providing violin makers with substitutes for ebony and ivory. “Tailpieces, pegs, and fingerboards can all be made from this material,” says Seebass, speaking by video conference from his instrument-lined studio in Salla, in Finnish Lapland. “It’s technically capable of being a peg. In the future there will be other species that we use for other instruments.”

Partones founder Armin Seebass

Seebass says he has previously grappled with the problems surrounding Brazilian pernambuco, the ingredient in bows that is also endangered because of excessive harvesting. The new composite will be comprised of natural plant fibers drawn from “agriculture and forestry” (specific sources are something of a company secret). With seed funding from the European Union Regional Development Fund, the company is building a small factory near Salla, which will combine handmade and machine production.

Aatsinki and Seebass plan to sell the raw materials through the company’s website and a network of distributors, beginning in Europe. In the meantime, the two entrepreneurs are visiting trade fairs and testing a prototype fingerboard on a student’s violin at the Sibelius Academy in Helsinki. In May, Partones was named one of the three winners of the Classical:Next Innovation Award, an annual prize given out by the music conference and trade show.

A violin using Sonowood components

Seebass acknowledges that no luthier wants to be associated with the destruction of tropical forests, a sentiment that extends to other instrument makers. In 2012, famed guitar builder Gibson paid $350,000 in penalties to settle charges that it had illegally sourced ebony from Madagascar for its fretboards. Since then, the company has embraced synthetic materials, including Richlite, for its fretboards on some models. Taylor Guitars, meanwhile, has spearheaded “The Ebony Project,” a reforestation initiative that, as of last year, had seen the planting of more than 1,500 trees in Cameroon.


The use of alternative materials will also help musicians avoid getting stopped when traveling through customs. The U.S. Lacey Act, which bans illegal trafficking of wildlife, was amended in 2008 to include wood that was harvested and exported illegally. Similar legislation has been enacted in Europe, Australia, and parts of Asia. CITES, an international agreement between 183 countries which establishes protection for animal and plant species, has also taken a tougher regulatory stance on tropical woods.

Younger buyers may be especially drawn to the new, natural alternatives. A recent study by First Insight, a digital research company, found that shoppers aged 22 and under are more willing to pay more for sustainable brands, compared to other demographics. Reilly of Vermont Violins is encouraged by such developments. “I am much more optimistic about the players being more concerned about the environmental impact than the color,” she says.

Philadelphia violin maker Christopher Germain has worked with Corene fingerboards and naturally sourced Sonowood tailpieces and sees benefits to each. “The Corene fingerboards are extremely stable and are machined to very accurate tolerances,” he says. “When they are finished, it’s very difficult to tell the difference from high-quality ebony. The Sonowood products have a more unique look, but they’re also very nicely designed and made.”

He adds, “Makers want to create the best product possible. As long as these new products can deliver the same capabilities and have a beauty of appearance, that’s desirable over a dwindling supply of ivory.”