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CASE STUDY · SPECIAL SOLUTIONS · INDUSTRIAL DESIGN

KOBU: from flat cardboard to a construction system

KOBU: cardboard toy design and product development

How can a sheet of cardboard become a construction toy? At A1Pack, we designed KOBU: a system of foldable, interlocking pieces developed from concept through manufacturing.

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PRODUCT DEVELOPMENT CASE STUDY · SPECIAL SOLUTIONS

Turning an everyday material into a play system

KOBU began as an A1Pack product development project. The challenge was to turn flat cardboard pieces into three-dimensional modules that could fold and connect to one another. The work combined industrial design, interlocking connections, prototyping and manufacturing. KOBU Classic brings together 100 pieces of six types in a microflute corrugated cardboard box.

Folded KOBU cardboard pieces arranged on a wooden table

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01 · The challenge: turning cardboard into a construction toy

At A1Pack, we set out to develop a construction toy using a material we knew well from packaging: cardboard. Each piece needed to fold, take on volume, hold its shape and connect to others to create different structures. We also needed a system that could be manufactured, transported easily and understood by its users. We therefore developed the shapes, connections and production process together from the start.

  • Goal: create a cardboard construction toy whose pieces could be combined in multiple configurations.
  • Design requirements: flat pieces, simple folding, repeatable connections and structures that hold their shape.
  • Opportunity: apply packaging design techniques to construction toys.

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02 · The concept: foldable modules and versatile connections

We designed KOBU as a connected system. Its cardboard components move from flat shapes to three-dimensional forms through folding, then connect without adhesives. The same piece can be used in different constructions. Six component types expand the assembly possibilities without requiring a separate fixed shape for every object. The concept also allows compact storage and distribution.

  • Modular architecture: six component types with complementary roles within one system.
  • Connections: folds and interlocking features that allow pieces to be assembled, joined, separated and recombined.
  • Scalability: a set of 100 pieces for creating different constructions without redesigning every figure.
KOBU cardboard towers and modular constructions on a wooden surface
A child’s hands assembling a KOBU cardboard toy piece

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03 · Technical development: prototypes, folds and cutting dies

A cardboard construction system depends on how the material behaves. We developed the geometries, fold lines and interlocking areas, then tested them in physical prototypes. We evaluated assembly, piece stability and repeated connections. We also carried out use tests with children to understand how the system worked beyond the design table. Those observations informed preparation for cutting and die-cutting, covering both the pieces and the packaging that holds the set.

  • Structural design: flat geometries that gain volume through folding and become part of the system.
  • Validation: prototypes and assembly and use tests to review folds and connections.
  • Production preparation: component and cutting-die definitions suited to cardboard converting processes.

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04 · Inclusive manufacturing and the finished product

KOBU combines cardboard toy design, technical development and manufacturing with social impact. Production was coordinated with Taller Protegido Los Tilos, a sheltered workshop in La Plata, linking the interlocking system to production and assembly tasks. KOBU Classic was presented in a microflute corrugated box containing 100 pieces of six types. For A1Pack, the project shows how knowledge of a material can lead to a physical product, a production model and a defined user experience.

  • Product: KOBU Classic, a construction system with 100 cardboard pieces of six types.
  • Manufacturing: cardboard converting, set preparation and participation by Taller Protegido Los Tilos.
  • Learning: product development requires decisions about use, structure, materials and manufacturing.
Adults and children building structures with KOBU cardboard pieces

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Designing a product includes designing the system that makes it possible.

With KOBU, A1Pack applied structural packaging design methods to a different type of product. Folds, connections, formats, prototypes and manufacturing decisions all contributed to a coherent system. The result is a family of cardboard components that can form multiple structures. This approach starts with understanding a material, exploring its possibilities and turning them into a real product.