The Secret Sauce to a Mustang's Design Is Still Clay and Tape

The heart of the car-design process still resides in the artistry used decades ago.
Designers molding a clay model of the current generation Mustang. You can see tape being applied to show the modeler the...
Designers molding a clay model of the current-generation Mustang. You can see tape being applied, to show the modeler the curves that need to be adjusted.Image: Courtesy of Ford

For all the technology that goes into fabricating a car, its design process is still stubbornly analog. A car designer’s most valued tools and materials sound not unlike a fourth grader describing how he made an art project: pens, paper, clay and tape.

It seems to make little sense. How can something like an automobile, which relies so much on technological advancements for safety and performance, rely on tools that are so completely basic? Don’t get it wrong. Automobile design certainly depends on technology. It’s standard practice to mock up designs as CAD files and 3-D print and mill components, but the heart of the design process still resides in the artistry used decades ago. The Mustang, which turns 50 today, still looks recognizably like a Mustang, and that's because generations of car designers have had to touch every curve they produce, to get each one right.

“A lot of people are surprised at the amount of real craftsmanship that goes into designing of a car,” says Moray Callum, design director of Ford Motor’s North American brands. “They don’t realize it’s not as simple as pressing a button on a computer, then a car comes out.”

>Each tape line that a designer lays communicates to the modeler a line needs to be altered.

Callum oversees the design of cars like the Mustang, F-150 trucks, the Fusion, and says despite increasing reliance on technology, using materials like clay and tape to nail down the nuances of a design is still very much alive and thriving in the industry. “Tape is quite an important part of our job, actually,” he says.

For those familiar with automotive design, this might not come as a surprise. Tape has long been used in the car creation process because of its ability to create a crisp, perfectly-straight line. This reaches back decades to when designers mocked up full-sized 2-D drawings using the stuff. Today, there are computer programs that do that for us, but tape is still used to craft important design cues on many of the cars you see on the road.

An Iterative Process

Each car at Ford (and every other major automaker) begins with a simple sketch. “Even though we use a lot more technical tools today, we begin by sketching traditionally,” explains Callum. From there, Master Modelers transform that 2-D drawing into a full-sized replication molded from a hunk of clay. That’s where the tape comes in.

The designers ultimately decided that there were enough Mustang-like visual cues that the car's signature "hockey stick" was overkill.

Image: Courtesy of Ford

Designers and modelers use the material as a common language. Each tape line that a designer lays communicates to the modeler a line needs to be altered. "Typically we go for lunch then come back and there's tape no the car, which basically says, OK that's great but here we've got some changes to do," says Larry Pelowski one of Ford's Master Modelers.

With the 2015 Mustang, designers were looking to widen the popularity of the car. Ford knew that drivers were familiar with the Mustang; it was just a matter of modernizing the car so it reached a larger audience. This meant getting rid of hallmark features like the "hockey stick," a graphic decal shaped like it's namesake that's been applied to the sides of Mustangs over the years.

To test this theory, designers would lay a stretch of tape in the traditional hockey stick shape on one side of the clay model, and leave the other side blank. “When we actually took it out, we had the underpinnings of a mustang and decided we didn’t really need it,” Callum explains.

The 2015 Mustang is lower and wider than the 2014 version by just a few inches, but those inches make a huge difference in how the car is perceived. It's difficult to grasp those nuanced details on a 2-D screen—you can't actually see how a car's curves play in the light or how your body aligns with the height of a door without seeing the vehicle mocked up and unvarnished, in clay.

Moreover, every single millimeter matters if you're trying to differentiate one car design from the hundreds that have preceded it. After each pass that the modeler makes, planing and shaping the clay, the designers then return, to request successively smaller and smaller variations. Only after that process is finished does the clay model get painted, so that the designers might appreciate how a real car would look.

So what’s the real value in doing it by hand? The answer is simple, says Callum. Driving a vehicle is a personal thing; you want it to feel safe and trustworthy, but also like a companion you wouldn’t mind spending a very intimate 30 minutes with every day to and from work. And while a computer-generated rendering might be precise, a computer model won't tell you what it's like to actually experience a car's design, standing next to it. “People still buy real cars,” he says. “They don’t buy digital cars.”