Reebok and Zellerfeld Unveil 3D-Printed Sneaker Built from Single-Material TPU

Footwear brand Reebok has collaborated with former NBA player Allen Iverson and 3D printing manufacturer Zellerfeld to release a revamped version of the classic 1996 Question sneaker. Dubbed the Reebok Question 96/26, the updated shoe is produced entirely through additive manufacturing, trading traditional multi-material assembly for a single-piece flexible TPU construction.

Variable Density and Single-Material Footwear Design

Unlike traditional shoemaking, which relies on stitching and gluing together distinct rubber soles, synthetic uppers, and foam cushioning, the Question 96/26 is manufactured as a continuous unit. The shoe relies entirely on flexible thermoplastic polyurethane (TPU), manipulating structural density across different regions of the model to deliver targeted mechanical properties.

By adjusting internal lattice structures and wall geometry during the print process, Zellerfeld creates localized rigidity and flex:

• Sole and Toe Box: High-density toolpaths provide the structural rigidity, wear resistance, and impact absorption needed for contact surfaces.
• Upper, Tongue, and Collar: Low-density, open geometry allows the TPU to stretch and flex comfortably, enabling a lace-free slip-on fit.
• Aesthetic Accents: Visual elements from the original design, including midfoot pods and brand logos, are integrated directly into the digital geometry.

Shifting from Prototyping to End-Use Production

3D printing in the footwear sector has historically served as a rapid prototyping tool or an aesthetic exercise for limited conceptual soles. The Question 96/26 highlights a broader industry shift toward using additive technology for final consumer products. By replacing multi-part shoe builds with single-material TPU production, manufacturers eliminate conventional tooling, reduce assembly steps, and produce items on demand.

Zellerfeld’s platform operates an on-demand print setup that caters to both major apparel brands and independent footwear designers. Similar initiatives across the footwear industry, such as direct-to-fabric printing and fully printed flexible shoes, demonstrate growing commercial interest in localized digital supply chains for wearable goods.

What This Means for South African Makers

For South African makers, designers, and small business owners, this release illustrates the practical potential of mastering flexible materials like TPU. While custom 3D-printed footwear requires specialized equipment and tailored slicing algorithms, the underlying design principles apply directly to desktop FDM printing.

Local workshops and engineering firms can apply variable infill densities and perimeter settings within standard slicers to alter stiffness across a single print without changing filaments. This technique is invaluable for custom gaskets, wearable prototypes, ergonomic grips, and flexible protective gear. Furthermore, as local interest in functional flexible prints grows, demand for reliable TPU stock and tuned extruder setups will continue to expand.

DC3D’s Take

Using flexible TPU to engineer variable structural properties in a single print is one of the most practical demonstrations of additive design. Rather than fighting material limitations, designing for variable lattice density turns a single material into a complete functional system. While commercial sneaker production relies on specialized industrial print farms, the core concept of controlling flex through geometry is something every maker can experiment with on a well-tuned desktop setup.