Candy is hygroscopic — it pulls water out of the air — and humid markets punish packaging that is 'mostly sealed'. The failure chain is predictable: moisture enters, sugar surfaces get sticky, wrapper printing transfers onto the tin, and in bad cases the tin's own exterior rusts on the shelf. All of it is specifiable away. Here is the playbook.
Understand the failure chain before picking a tin
In a humid warehouse or a coastal summer, the sequence runs: humid air enters through a loose lid → sugar surfaces turn tacky → wrappers stick and print transfers → condensation on the tin interior in temperature swings → in extreme cases, exterior condensation rusts the finish. Every stage has a packaging counter-measure, and the cheapest one is choosing the right lid structure up front.
Lid structure: this decision buys most of the protection
| Lid type | Moisture resistance | Verdict for candy |
|---|---|---|
| Slip lid, standard tolerance | Moderate | OK for dry climates and fast-turnover retail |
| Slip lid with tight pull force + inner press lid (double lid) | High | The sweet spot for gifting and humid markets |
