When the inspection happens
A pre-shipment inspection takes place when production is finished and at least most of the goods are packed in cartons, usually a few days before loading. The inspector draws samples at random from the packed lot, opens cartons and runs agreed checks against the approved golden sample and the written specification. If the lot fails, there is still time to sort, rework or remake at the plant. If it passes, the inspector can also supervise loading.
The checks and the acceptance levels are agreed per order before production starts. Sampling plans based on recognised acceptance quality limits are common; the number of pieces drawn and the defect limits per category are a stated working default, confirmed per order.
1. Identity and count
- Item codes, capacities and colours match the purchase order.
- Carton count matches the packing list, and pieces per carton match the agreed pack count, for example 200-300 sets for thermoformed PP boxes or 300-500 for injection cups.
- Lot and date labels are present on each carton.
Count errors are the simplest defect and among the most expensive downstream, because a marketplace or distributor receives short cartons and charges back.
2. Dimensions and gram weight
Outer dimensions are measured with calipers on a set of samples and compared with the specification, such as 170x115x51 mm for the 750 ml reference box. Gram weight is weighed on a scale against the target, 19.6 g for that model. Weight is the quickest way to detect a thinner wall or a change of material, both of which affect stiffness and lid fit. A tolerance band is agreed per order; a lot that is consistently light is a finding even if every piece looks correct.
3. Lid fit and closure
- Lids close and open with a reasonable force, checked on lids and bases from different cartons and cavities.
- Lids stay closed when the container is held by the lid edge or squeezed gently.
- Hinged clamshells close and reopen without cracking at the hinge.
- Storage lids with seals sit evenly, and vacuum container valves hold when tested per specification.
4. Functional tests
For food containers the key functional checks are agreed per order from the standard list:
- Tilt and inversion with water: no visible escape within the agreed time, so the item is described as leak-resistant in the standard tilt test, confirmed per order.
- Drop test of a filled container from an agreed height.
- Freezer at -18 degrees C, then lid opening and closing without cracking.
- Microwave heating per the supplier marking, with the lid removed or vented where marked.
- Hot water per the supplier's stated range, where the item is used for hot fill.
- Odour check on a sealed sample.
Migration testing is not part of a pre-shipment inspection; it is done by a third-party lab on samples earlier in the program. The inspection confirms that the lot matches the material and item that were tested.
5. Appearance
- Clarity of clear parts, and no haze, streaks or bubbles beyond the approved sample.
- Black spots, contamination, short shots and sharp flash at the rim.
- Scratches and scuffs on clear storage boxes and organizers.
- Colour against the approved sample, especially for black base and white items.
6. Print, labels and paper
Printed lids and cups are checked for position, colour and a tape adhesion and rub test. Sleeves and labels are checked against the approved artwork and for barcode readability. Paper boxes are checked for print registration, crease quality, glue lines, window film position and, where agreed, bursting strength and edge crush on samples.
7. Packing and cartons
- Items are bagged or sleeved before cartoning, with no loose food contact items.
- Cartons are dry and undamaged, with the agreed board grade and marking.
- A stacking or compression check on a filled carton where the order specifies it.
- Nested items denest without sticking.
Extra checks for storage and organizer lines
Reusable storage items are kept for years, so the inspection leans towards durability and fit rather than single-use performance. For collapsible boxes, the inspector folds and unfolds samples a set number of times and checks that hinges lock and do not whiten or crack. For shoe boxes and clothes boxes, doors and lids are opened repeatedly and stacked boxes are loaded to the agreed height. For fridge bins, the outer size is checked against the shelf dimensions in the listing, typically around 315x157x89 mm for the common eight-piece set. For vacuum containers, the pump and one-way valve are tested on a set of samples to see that the lid holds. For cosmetic and desk organizers in PS or acrylic, the focus is on scratches, cracked corners and drawers that run smoothly. Retail packaging is checked for barcode, size statement and material of each part on the box.
Defect classes and actions
| Class | Examples | Usual action |
|---|---|---|
| Critical | Wrong material, contamination, failed tilt test on a food item | Lot held; root cause and remake |
| Major | Lid does not fit, gram weight out of band, cracked hinge, wrong count | Sort or rework, reinspect |
| Minor | Small flash, light scuff, slight print offset | Accepted within the agreed limit |
What the report should contain
A useful report gives the order and item details, the sampling plan used, results per check with numbers rather than ticks, photos of defects and cartons, and a clear pass, fail or pending verdict. Photos should show products, cartons and measuring tools, without people. The desk files the report in the program file next to the golden sample record, so the next lot is inspected against the same reference.
Inspection and the rest of the program
Inspection catches a bad lot; it does not make a good plant. Programs with few failures usually started with a scoped factory audit, a clear specification and an approved golden sample from the sample process. Inspection timing sits inside the batch lead times on MOQ and lead time, typically 7-15 days from stock and 15-30 days for printed items, confirmed in writing per program. Send your items and checks through the quote form to have an inspection plan drafted.