By Nicolas Grizzle
Carbon fiber in the string world has been used commercially since the 1970s, with orchestral stringed instruments coming into their own starting in the ’90s. Like any new technology, there have been many innovations applied to these instruments since their formative years, including the construction of the material itself. This is unique to carbon fiber, since trees aren’t about to start growing their fibers differently to satisfy a human urge to innovate.
Carbon fiber in raw form is called a tow, and it’s similar to yarn in that a tow is made up of bundles of carbon fibers. Tows are made with pressure and heat, and each tow can contain anywhere from 3,000 to 12,000 fibers. Those are typically made into a fabric, which is then layered into a mold, coated with resin, vacuum-sealed, and hardened to create the pieces for assembly of the instrument. There are two common types of carbon-fiber fabric used in instrument making: woven and unidirectional.
Generally, carbon-fiber instruments are louder and deeper than their wood counterparts. They are more weather resistant and durable than wood, too. But not all carbon-fiber instruments are created equal, nor should they be. A super-sensitive bow, for example, that responds to a player’s every nuance would be quite frustrating to the hands (and ears!) of a beginner. But different construction methods yield different results, and as the market has developed, more options have developed along with it.
“It’s not about these absolute paradigms of wood versus carbon fiber, or woven versus unidirectional,” says Rachael Ryan Dahlgren, director of sales, marketing, and artist relations for CodaBow, which makes bows with woven and unidirectional carbon fiber. “If you tend to focus on these absolutes, it’s kind of like asking what’s the most important part of a symphony—it’s not any one, it’s the combination of all of them to create that piece.”
Luis & Clark, a company that started working with carbon fiber in the early ’90s, uses both woven and unidirectional fabric in its instruments. “Using unidirectional only won’t make an instrument that is strong enough or durable enough,” says vice president Stephanie Leguia. “If an instrument is made only out of unidirectional carbon, it is liable to delaminate either quickly or over time and the performer will have nothing to play.”
Andrew Glasser of Glasser Bows, a Bronx-based company that produces bows, instruments, and accessories, says that they also use a variety of different weaves in their instruments. “Glasser uses all types of carbon fiber in bows and instruments, both unidirectional and woven,” he says. “Most importantly our braided carbon-fiber bows are [made] with dry carbon fiber, not a piece of woven carbon fiber wrapped over a fiberglass shaft.
“For the instruments, the magic is in both the recipe and the construction. It’s easy to create a hard shell, but instruments need warmth. The difficulty is in emulating the density and stiffness of spruce and maple so the instrument sounds like real wood.”
Within the world of woven carbon fiber, there are many different options. Luis & Clark’s fabric is made with a 2×2 twill-weave construction. This popular pattern is recognizable by the diagonal lines produced by the over-over, under-under weave of the fiber tows. It results in a looser weave that is good for forming into complex shapes.
In terms of recent technological advances to carbon-fiber technology, Glasser says the past five years have yielded improved resin systems. “Also,” he says, “many companies utilize advanced machinery for producing pre-preg woven carbon fiber [fabric pre-impregnated with resin] using hot melt machinery as opposed to solution coating. The pre-pregs have helped advance tone, ease of construction, and helped reduce the cost.”
Mike Donahue, general manager of Clear Carbon and Components, which manufactures Luis & Clark’s instruments, points to more subtle advancements, like the development of a wider variety of choices in fabric for visual aesthetic, like wider, thicker, or different patterns. The innovations come from applying the material in different ways.
“All good carbon-fiber instruments are made from multiple layers of high-quality, carbon-fiber material,” says Stephen Crisafulli, vice president of Gatchell Innovations, whose carbon-fiber instruments and bows debuted in 2017. “Each layer has its own characteristics and is applied to the next layer in a way the designer thinks best. So each maker will have their own goals that will drive their approach for creating the overall material needed to achieve the result they are looking for.”
Though technological advancements may add to an instrument’s versatility and have an effect on tone and playability, material is only part of the equation, says Crisafulli. “Of course, the material used is extremely important as is the way the fiber is layered. But this is only the starting point,” he says. “The designers of our instruments are makers of traditional wooden bowed-stringed instruments. They understand what makes a good instrument good.”
And despite its versatility as a material, there are some parts of an instrument that may not be suited for carbon fiber, regardless of its fabric construction. At Luis & Clark, for example, all bridges are made of wood. “Our experiments with carbon bridges showed us that wood makes a better sound,” says Leguia.
Not each instrument will resonate with every player, especially at different skill levels. And some think of bows like wands in the Harry Potter world—they may not “choose the wizard,” per se, but when you find the right one, you can certainly feel it.
For example, CodaBow’s recently introduced Marquise series uses solely unidirectional carbon fiber to increase suppleness and sensitivity “for a deep string connection, which is what traditional classical professionals need in their performance,” says Dalghren. “Just because we use the unidirectional [fabric] in our highest-end bow, that doesn’t mean it’s a better bow—it’s better matched for those high-end professional players,” she says. “You wouldn’t want to put a very high-end, very sensitive, supple bow in the hands of a student because it wouldn’t be well matched for them; they wouldn’t be able to handle it.”
So what does the future hold for carbon fiber? Applying the fabric in ways that allow for greater customization is a big part of CodaBow’s plans. “Especially at that high level, when it’s not just a question of matching a certain style or level, but matching an individual taste, an individual approach, trying to partner with artistic sensibilities,” says Dalghren.
At Luis & Clark, Leguia is focused on consistency. “In terms of tone, we believe that our instruments have a tone that can not be surpassed and exquisite workmanship that is unparalleled,” she says. “We aren’t going to change anything.”
Crisafulli feels each maker will find their own methods, using the best type of material for each particular instrument. “We do believe that advances in carbon-fiber materials will continue to be an important piece of the puzzle,” he says. “However, we do not think that each maker will move in one ‘best’ common direction, favoring one method over all the rest.”