Bow Maker Michael Duff’s New Line Includes Hybrid Materials

By Stephanie Powell

Due to the dwindling sources of many traditional materials used to make bows, some makers have begun working with untraditional materials. Michael Duff began moving away from the usual supplies by developing a bow stick made of synthetic resin instead of pernambuco, and continued his work by using African Blackwood for his frogs instead of ebony. Berg Bows’ Tourte-Voirin bow line—for violin, viola, and cello—includes both the synthetic resin stick and the “stabilized” blackwood frog, which is created through a process wherein resin is infused into the wood.

We received two review models: one viola and one cello bow. Both left our reviewers impressed with their individual handling, balance, and tone.

In the viola model, our reviewer noted the handling in the lower half of the bow as well as agility at the tip. “There’s a certain amount of tip weight [you need] to produce a certain type of piano on the tip, and that’s there,” she said. As for weight, she said that, while she prefers a lighter-tipped bow due to a wrist issue, the overall balance handles smoothly and consistently. “It feels very comparable to something like Sartory models to me,” she said. The composite material offers players flexibility and the mobility of a wooden bow that manages to pull a good tone consistently.


“I would play it with total confidence and not worry about my tone,” she said, and “where I would have to do most of my playing has plenty of response.” The bow’s construction affords for an excellent draw all the way out to the tip. Our reviewer would recommended this bow to an advanced student, a semi-professional, or a professional.

As our cello-bow reviewer alternated between playing J.S. Bach and “Ashokan Farewell,” she couldn’t help but discuss the bow’s response. “It releases some sort of resonance that brings up the bottom end,” she said. In a comparison to her current bow, she noted, the weight appeared to be similar, but it took less effort to achieve and sustain a forte with the Berg Bow. It’s lightweight, she said, but easy to maintain a consistent tone.

“It really unlocked some rich tones of my cello that I haven’t heard before,” she added. “It pulls rich tones from the high to bottom end and is nice in both registers.” She also noted its comfort, and thought it felt like an extension of her arm, “which is how a bow should feel.”

“I feel like my other bow has just been kind of releasing surface tones now that I’ve played this,” she added. She also recommends the bow for more advanced players.

Berg Bows Tourte-Voirin bow line

  • Synthetic resin stick
  • Stabilized African Blackwood frog
  • Weight: 57 grams (violin); 67.5 grams (viola);
    83.25 grams (cello); weights can be customized
    upon request
  • $7,500 (violin); $7,500 (viola); $8,000 (cello)


Berg Tourte-Voirin cello bow
Berg Tourte-Voirin viola bow