# Discarded tennis balls transformed into wearable shoes Designer Soroosh Riazi Isfahani cuts used tennis balls into shoe components using 3D-printed guides. - **Source:** [design archives | designboom | architecture & design magazine](https://brifing.si/source/11868f8d-1e20-41ac-bc2d-8c5af32d721b) - **Published:** 2026-08-04 - **Topic:** [Design & UX](https://brifing.si/c/design) - **Original article:** - **On Brifing:** https://brifing.si/s/76ed3232-11e5-4e70-9806-807cae34268f ## Transforming tennis balls into shoes Designer Soroosh Riazi Isfahani repurposes the springy rubber and grippy surface of used tennis balls into footwear components. Each ball is precisely cut using custom 3D-printed guides to create repeatable parts. The cutting process yields curved bands and cup-like sections that are strategically placed in different areas of the shoe. ## Design preserving material properties Isfahani's initial attempts involved grinding tennis balls and mixing them with natural rubber, which erased the ball's original characteristics. The new approach uses each ball as a prefabricated component with predetermined shape, texture, and thickness. This preserves the tennis ball's curved form and textured surface while showcasing wear patterns from different brands. ## Solution for tennis industry waste Approximately 400 million tennis balls are produced annually, with very few being recycled. The felt covering is tightly bonded to the rubber underneath, making separation difficult in standard recycling systems. The SLICE project offers an innovative solution by directly utilizing the ball's geometry in shoe design. ## Prototype's distinctive features The prototype shoes feature overlapping yellow curved sections around the toes and heels, with white seam lines appearing like fragments of a larger drawing. The broad, slightly bulky design resembles a material study more than a streamlined performance sneaker. The shoes have already been tested on tennis courts. ## Manufacturing process details Each tennis ball is secured using specially designed 3D-printed guides, while a blade follows a predetermined path across its surface. These cuts transform the pressurized sphere into footwear components. Wider pieces wrap the forefoot, while narrower strips run along the sides, connected by black stitching and cords around an inner structure. ## Sustainability aspect of the design The SLICE project treats tennis balls as engineered materials with existing form, resilience, and recognizable visual identity. A precise cut opens the sphere into curved building blocks. The shoe grows directly from the repurposed object, with every fuzzy strip clearly revealing its origin. ## Future challenges and development Currently an experimental footwear project and 2026 James Dyson Award entry, SLICE would require faster cutting and sorting systems for large-scale production. Variations in felt condition and rubber thickness could affect assembly behavior. Further testing is needed for traction, water absorption, repeated flexing, and felt abrasion. ## Innovative approach to sustainable fashion The SLICE project presents a striking example of direct and creative reuse of waste materials. The transformation of tennis balls into shoes pushes the boundaries of sustainable design while offering consumers unconventional aesthetics. This approach could inspire recycling solutions for other sports equipment. ## Sources covering this story - https://www.designboom.com/design/slice-discarded-tennis-balls-wearable-shoes-soroosh-riazi-isfahani/ — --- _Summary written by Brifing from the original reporting. Copyright in the original article belongs to its publisher; read the full piece at the link above._