The project
Pocketlock is a magnetic closure made by KapLock ApS that fits inside a garment pocket and keeps it shut. It is a two strap solution with embedded magnets, around 10 cm long, sized to run along the opening of a pocket. The product is now in production and on sale. The work described here was prototyping and testing during its development.
The approach
The whole problem is a contradiction. The closure has to hold firmly enough that a pocket never opens on its own, and release easily enough that it never feels like a struggle to get into. Those two requirements pull directly against each other, and the window between them is narrow. Finding it is not a calculation, it is a lot of physical testing with real hands.
How it was made
Prototypes were 3D printed and cast in silicone so that versions could be handled and judged rather than only modelled. The testing worked through magnet types and strengths, different arrangements of magnets along the straps, the spacing between them, where they sat relative to the pocket opening, and the tapes holding everything in place. Each variable changes how the closure feels, so they had to be tried in combination rather than one at a time. These prototypes are not the product being sold today. Production was carried out elsewhere and the design continued to develop afterwards.
Where the same approach works
Some products can only be resolved by making them. When the requirement is a feeling rather than a measurement, how firmly something holds and how easily it lets go, the fastest route is a lot of cheap physical versions and an honest judgement about each one. The same approach suits closures, fasteners, grips, wearables, and any product whose success depends on how it feels in use.
