Cardboard prototyping uses cardboard, foam board, tape, and other cheap craft materials to build physical models of products, spaces, or service touchpoints. It applies the paper prototyping philosophy to the third dimension: get something in the user's hands as quickly and cheaply as possible, even if it looks nothing like the finished product. The material constraints of cardboard force designers to focus on structure and interaction rather than aesthetics, which is exactly where the most important design questions lie at the early stages of physical product development.
What It Is
A cardboard prototype is a three-dimensional model built to test physical interactions, spatial relationships, form factor assumptions, or service environment layouts. It can represent a physical product (a medical device, a packaging design, a tool), a spatial configuration (a retail layout, a kiosk station), or an environmental design element (signage, wayfinding). Like paper prototyping for digital interfaces, it is designed to be thrown away: the learning, not the artefact, is the output.
How to Run It
- Define the specific design question you need to answer with the prototype: ergonomics? Scale? Flow? Interaction sequence?
- Gather cardboard, foam board, paper, tape, scissors, and any available props.
- Build quickly and roughly — the goal is testable, not beautiful.
- Bring real users into interaction with the prototype: ask them to perform a realistic task using the model.
- Observe physical interaction: how do they hold it? Where do they look? Where do they hesitate?
- Capture findings and iterate the prototype before the next round of testing.
When to Use It
Cardboard prototyping is essential in physical product design, packaging, spatial design, and service design involving physical touchpoints. It is particularly valuable in medical device design, consumer electronics, kitchen and home products, and any context where the physical ergonomics and form factor are as important as the functional specification. Use it whenever the physical experience of holding, operating, or moving through a design matters.
Tips for Success
- Build to approximate scale whenever ergonomics are being tested: a phone-sized cardboard model tests grip differently from a tablet-sized one.
- Make multiple variants simultaneously — a different card-board model for each design direction takes thirty minutes, not three weeks.
- Do not apologise for the roughness of the model: tell participants 'we made this this morning to test an idea' and they will engage with the concept rather than the craft.
- Take photographs at every stage of the build: the construction process itself often surfaces design decisions you did not know you were making.
