Bench Answers
Short, precise answers to the questions that come up most often at packing benches and design reviews. Each links back to a deeper page.
Centre seamFinal check
How much cushioning space should I leave around a fragile item?
Many carrier guides suggest around 5 cm (2 in) of cushioning between a fragile item and each wall. Use it as a starting point and confirm with drop trials. More on cushioning.
Is double-wall corrugated board always safer?
No. Double wall adds compression and puncture resistance, but poor fit or weak cushioning can still lead to damage. Match board strength to the hazards and product weight. See box structures.
What is the difference between ECT and burst strength?
Edge Crush Test measures resistance to crushing along the flutes and predicts stacking strength. Burst strength measures resistance to a rupturing force across the face, closer to puncture resistance.
Why do boxes collapse in humid conditions?
Paper fibres absorb moisture from the air and lose stiffness, so corrugated board can lose a large share of its compression strength in high humidity. See moisture barriers.
Do I need a laboratory to test my packaging?
Certification requires a qualified laboratory. For design decisions, a consistent in-house drop and inspection routine catches many failures early. See pack testing.
Which test standard applies to parcel shipments?
ISTA 3A is designed for packaged products shipped through parcel delivery systems. ISTA 1A is a simpler integrity test, and ASTM D4169 offers modular distribution cycles.
Are air pillows good protection for heavy items?
Air pillows are best as void fill for light items. They can puncture or lose pressure, so heavier or fragile items usually need engineered cushioning such as foam, moulded pulp or corrugated inserts.
How do I size a desiccant?
Desiccant quantity depends on enclosed air volume, barrier vapour transmission and journey duration. Standards such as DIN 55473 define desiccant units, and suppliers provide sizing guidance.
When does a reusable shipping container make sense?
Reuse works best on predictable routes with reliable returns, such as business-to-business deliveries or subscription models. The pack must survive many cycles and fold or nest for return.