A prototype is a question you can hold. The goal is not to make the thing — it is to find out whether the thing is right, as cheaply as possible.
Pick the right fidelity
- Paper and card: packaging, layouts, app screens you can "tap" with a finger. Minutes.
- Foam board and hot glue: furniture, displays, stands. An afternoon.
- Clickable mock-up: screens linked together in a free design tool. A day.
- 3D print or laser cut: shape, fit and feel of a physical product. Many UK makerspaces and online bureaux will print from a file.
- Working prototype: only when the earlier ones have answered the big questions.
Test with one question
Before you show it to anyone, write down the one thing you want to learn: "Can people open the box without instructions?" "Do they find the menu?" Watch, do not explain. If you have to explain it, that is your answer.
If your product touches skin, food, children or electricity, a prototype is not a finished product. UK product-safety rules apply before you sell anything — check GOV.UK and the relevant standards.