Model-making has been a tool for designers for thousands of years. You try something out, tweak it, scrap it, and try again. It turns the imagined into the real, and lets the idea speak for itself.

Computers haven’t changed this. No desktop design simulation, VR goggles, or even lush artistic rendering can change the value of having an actual thing in front of you to look at and touch. So it should come as no surprise that physical modeling still thrives in design studios around the world — particularly in the automotive industry. It’s the primary tool that designers use to craft their vision, and by far the easiest way for production teams and execs to fully grasp and evaluate the work, both aesthetically and practically.

It also has a way of breathing life into a design. “What is good about clay modeling is that it enables us to intuitively create a form that appeals to people’s hearts,” says Norio Terauchi, chief clay modeler at Mazda. “While making repeated slight changes, a perfect line gradually emerges. I think this is a sensuous beauty that is difficult to reproduce through digital technology.”

Clay — or, more specifically, industrial plasticine — is the favored medium for design modeling because it’s easy to build with and easy to manipulate as the work evolves. Teams spend hours working with dozens of tool types (including metal rakes, loops, texture tools, wrinkle tools, and steel blades) to craft the perfect lines. The clay is usually built up from a smaller-scale foam structure supported by steel or wood. It’s thick enough to allow for removal and shaping of the clay, but not so thick that the model ends up weighing thousands of pounds. (A cubic foot of standard industrial plasticine weighs 90 pounds.) The clays come in an assortment of consistencies, colors, and textures to suit multiple applications; the same material also is employed by artists, special-effects crews, and sculptors.


Critically, though, it’s not merely shape and design study that benefits from clay modeling. Terauchi notes that clay modeling also is important for evaluating how light interacts with the design. “As a modeler, I care particularly about [making] reflected light look beautiful,” he says. “If something is wrong with the surface, light doesn’t reflect back smoothly. I fine-tune the surface finish with aluminum film over and over again.”

The film that Terauchi uses — whether working on Mazda production models or heavily stylized concept cars, such as the groundbreaking RX-VISION unveiled at the Tokyo Motor Show last fall — is specially designed to be applied to clay models. It can give the final products a startlingly finished quality — so much so that observers may not even realize they’re looking at a model. The surfaces can be polished to a gloss and painted for a variety of finish options. Generally, cars represent perhaps the upper limits of the practicality of 1:1 modeling, and trying to model anything larger represents another tier of effort and space requirements. So, in the automotive world, companies tend to take it pretty seriously.


Indeed, the big brown models sitting statically in design studios represent just a slice of the medium’s overall usefulness to car designers. The material holds fine details without cracking or drooping, so precision molds can be made from the model. It’s also surprising to see the extent to which the physical world of clay modeling and the digital design universe co-mingle: Clay can be CNC-milled (allowing for a degree of quick and repetitive precision manufacturing as the designers progress with their work) and it can be digitally scanned, allowing the changes brought on by the model to be re-integrated into the virtual design workflow.

For its part, Mazda is uniquely drawn to the use of clay modeling in its design work: Despite its relatively small size, “Mazda consumes more clay than any other manufacturer,” according to MX-5 Miata Chief Designer Masashi Nakayama. From the company’s earliest models like the beautiful, rotary-engined Cosmo Sport of the 1960s to the current MX-5 roadster and CX-5 crossover — among many others — all have benefited from the meticulous construction of clay models. Mazda’s design teams feel that the process results in higher-quality design, as adjustments can be made to both interiors and exteriors to attain degrees of design unity that can’t easily be duplicated by working just with digital models. The process at the carmaker is uniquely collaborative, with the clay modelers often using their expertise with physical realities to help influence a design’s direction.


“Sometimes, the form envisioned by the designer can’t be created in the real world,” Terauchi says. “In such cases, I make an alternative proposal from my point of view as a clay modeler. That’s not at all unusual at Mazda. I can make those kinds of proposals because I am always thinking about what the design is intended to express.”

At this heavily design-driven Japanese manufacturer, getting your hands dirty has many benefits.

This post is a sponsored collaboration between Mazda and Studio@Gawker.