The most common complaint we get is not about quality; it is about breakage in transit. A customer opens a carton and finds 15 cracked mugs, and the first instinct is to blame the factory. The reality is more complicated: breakage rates are mostly decided by packing density and carton weight, not by the mug itself. Here is how breakage actually happens and what you can do about it.
What Breakage Rates Are Normal
With correct packing, expect 0.5-2% breakage on a sea freight shipment, which means 5-20 mugs per 1,000. Below 0.5% is excellent, and anything above 3% means either the packing is wrong or the cartons are being handled badly at a specific port. Most buyers never see these numbers because suppliers replace broken pieces without telling them. Ask for the actual breakage figure; a supplier who tracks it is a supplier who packs properly.
The Drop Test That Predicts Everything
We test every packing configuration with a 1-meter drop onto concrete on the corner and the edge, per ISTA 1A-style standards. A mug packed in a snug EPS sleeve inside a corrugated carton survives; the same mug wrapped in two sheets of bubble wrap in a loose box often does not. The test costs nothing and catches 90% of packing problems. If your supplier cannot show you a drop test video of your exact packing, ask for one before production.
Packing Density: The Trade-Off Nobody Mentions
Freight is charged by volume or weight, whichever is higher, and ceramic mugs are heavy: a standard 11oz mug with packing weighs 350-450g. To cut freight cost, suppliers pack more mugs per carton, which raises breakage risk. A 20kg carton of tightly packed mugs can crack under its own weight when stacked six pallets high in a container. Our maximum is 24 mugs per carton with EPS dividers, and we put the 18-24 kg/m³ EPS density spec in the packing list. Cheaper foam looks the same and performs worse.
Where Damage Actually Happens
In our claims data, most damage is not at sea; it happens at the destination port and in the last-mile truck. Containers sit in the sun, pallets get forklifted hard, and local couriers stack heavy cartons on top of lighter ones. That is why the packing must survive a 1-meter drop and a 60kg carton stack, not just the ocean. If you see a pattern of corner damage, it is a handling problem at your port, and the fix is stronger corner protection, not a different mug.
How to Protect Yourself as a Buyer
Three rules. First, agree the breakage allowance in the contract: we replace anything over 2% free of charge, and you photograph damaged cartons before signing the delivery note. Second, insist on a drop test video of your exact carton configuration before production. Third, if you are re-packing mugs locally into gift boxes, keep the EPS sleeve for shipping; the gift box alone is not enough protection. Buyers who follow these three rules file almost no claims.
Breakage Is a Packing Problem, Not a Mug Problem
A 0.5-2% breakage rate is normal and mostly preventable with a proper drop test, correct EPS density, and a sane carton weight. Agree the allowance in writing, demand the test video, and photograph damage at delivery. Kontaktieren Sie COMAIN CERAMIC and we will send you our standard packing spec and drop test video with any quotation.