Pick up one of Callaway’s ERC Soft, Supersoft, or Supersoft MAX golf balls and they won’t feel soft in your hand. Subject them to a titanium-faced clubhead traveling at 120 miles per hour, however, and that rigid little orb will quickly deform into an ovular glob before springing back into shape. That’s true of all golf balls, but the extra softness found in Callaway’s balls comes from their shells and a fascinating material called Paraloid

What’s the spin?

Callaway designed its Supersoft golf balls to spin, but not break

Golfers demand different things from a golf ball depending on what kind of shot they’re hitting. “In golf, there’s this concept called spin separation. When you hit a driver shot, you want very low spin because that will give you more distance,” says Petra Petrich, senior research manager of golf ball research and design at Callaway Golf. “But, as you get around the green, you want more spin.” On shorter shots, that faster backward rotation will cause the ball to grab onto the green or fairway once it lands rather than continuing to roll past your target.

In order to get that spin that golfer’s short games require, ball manufacturers, implement softer covers—but that comes at a price. “The most premium products utilize urethane, which is softer than the less expensive products, which typically use an ionomer cover,” says Petrich. So, the balls are typically more expensive and simultaneously less durable. In order to solve the problem, Callaway looked for a material that would improve durability without cutting into the spin performance. The answer was an impact modifier from DOW called Paraloid, which adds resilience to the cover without making it harder. 

What is Paraloid?

Like so many industrial chemicals, Paraloid is something you’ve probably interacted with, without ever knowing what it is. It’s classified as an impact modifier and you can find it in everything from appliances to sporting goods. “These powders consist of extremely tiny rubber particles on the order of 100 to 200 nanometers,” says Ian Drake, global technical director of Dow Plastics Additives. “They typically go into engineering resins that are sold into durable goods applications like appliances. Anything that needs impact toughness or ductility applications.” Ductility refers to a material’s ability to deform without failing, something a golf ball does every time you hit it.

Callaway relies on Paraloid to stop cracks from propagating in the outer shell of its Supersoft golf balls. Specifically, the material combats a phenomenon called “cover cut.” According to Petrich, “cover cut is when the wedge hits the ball and you get score line marks.” Those marks immediately affect the aerodynamics of the ball, and quickly turn into bigger cracks with more use. Paraloid can help prevent them in the first place. 

There are plenty of other materials that perform similar tasks, but Callaway found Paraloid particularly compelling because of its color. The company has tried other materials such as graphene in the past, but those discolored the balls. Callaway molds the color directly into their balls instead of painting them, which means the color from any additive can come through.

The material wasn’t originally made for golf, but according to Petrich, that’s part of the challenge when designing balls. “This is not a unique story in terms of a technology that we pulled off a shelf and applied in a way that has a benefit for us,” she explains. Her team regularly subjects unusual materials to the high-impact, high-speed forces that golf involves. “Even when you think about car bumper testing and things like that, we’re dealing with very high smash factors.”

How does it feel when you hit it?

Callaway designed its Supersoft golf balls to spin, but not break

Because the Paraloid only exists in the cover, experienced golfers will mostly really feel the difference on shorter shots around the green or with the putter. The concept of feel often comes back to the sound the ball makes when the club hits it.

While a soft cover can provide the desired spin around the green, softness inside helps keep that same spin in check when you hit it off the tee. “The core is the largest volume of the ball, Petrich explains. “The softer that core is, the less spin you’re going to get off the driver.” The harder you hit the ball, the more you’re going to affect the material deeper inside the ball itself. By tweaking the materials and their densities at various points inside the ball, manufacturers can tweak how it will perform with a variety of clubs and under varying conditions. 

Callaway’s Supersoft balls provide a solid middle ground when it comes to performance that’s accessible to most players. “If you were to hit the same wedge shot with a urethane ball, they tend to have a lower launch so you get that low skidder effect,” Petrich explains. “Ionomer balls have a more vertical trajectory and that allows them to land more perpendicular that will also cause them not to roll out a lot. This particular cover puts the trajectory in the middle ground.” No matter how you hit it, though, the Paraloid will help keep it from cracking and saving you some money at the pro shop. Unfortunately, it can’t help if you hit it into the water hazard.