Packing 101: How to Fold and Polybag Custom Bags Efficiently

Why packing is a cost line, not an afterthought

Packing sits at the end of the schedule, so it is usually the part a campaign team thinks about last. That is precisely why it causes damage. A packing specification written after five hundred units are already finished produces cartons that are too large, polybags too thin to survive a container, and pack-out patterns that fail under compression during transit. Every one of those failures converts into a backer ticket, a replacement unit, and a handling charge at the fulfilment warehouse that nobody had budgeted for.

There are three places a reward programme quietly loses money on packing: carton volume, damage rate, and pick error rate. Carton volume is the largest and the least visible, because it is billed as freight rather than as packing. A tote folded flat to 4 cm instead of 3 cm, multiplied across a 500 pcs run, adds real cubic metres to a shipment, and ocean freight is quoted on cubic metres rather than on units. The saving from cheaper board is normally repaid several times over in the freight line.

The remedy is unglamorous and cheap: write the packing specification at the same time as the tech pack, and quote it as part of the same RFQ. A production partner reading a complete pack can return a unit cost, a sampling estimate, a production window and a packing cost in a single exchange. A packing decision taken after the goods are sewn cannot be changed without re-handling finished units. The same logic applies to the QC gate, which is why our bag QA and QC process is written into the pack rather than negotiated afterwards.

There is a second reason to write the packing specification early: it is the cheapest place to fix a freight problem. Changing a fold method on paper costs nothing. Changing it after four hundred cartons are sealed costs a re-handling operation, a second packing pass, and a delay that lands on the published delivery month. Packing is specified once and paid for on every unit, which is the definition of a decision worth taking slowly and confirming on a real sample.

Minimum order quantity

500 pcs per style / colourway

Sampling

6-10 working days (12-15 for complex builds)

Bulk production

35-50 days after deposit + approved pre-production sample

Inspection

AQL 2.5 to ISO 2859-1

Trade term

FOB Xiamen

Payment

T/T 30/70

Production floor

4,950 m² SGS-verified, 137 staff, 7 lines, 149 machines

Monthly capacity

200,000 pcs per month

Programme contact

service@junyuanbags.com

The packing SOP: six stations that beat ad-hoc folding

Ad-hoc packing is what happens when a team folds units on a table and fills cartons until they are full. It produces inconsistent pack counts, mixed colourways inside a single carton, and labels applied to the wrong boxes. A station-based SOP costs nothing to specify and removes most of that variance. Each station has one job, one pass or fail test, and one record, which is what makes a packing error traceable after the container has left.

1. Station 1, verification: scan the unit and confirm style, colourway and size against the packing list before it enters the line.
2. Station 2, fold: fold to the written method for that format, using a template or jig wherever a flat thickness is specified.
3. Station 3, insert: add desiccant, tissue, care card or retail insert in the stated order and orientation.
4. Station 4, polybag: insert to the stated gauge with the closure on the stated edge, then align the printed warning.
5. Station 5, label: apply the unit barcode and any market labelling, then scan-verify against the packing list.
6. Station 6, cartonise: pack the stated count, seal, weigh, apply the carton number and record it on the packing list.

Layout matters less than sequence. What makes the SOP work is that each station hands a verified unit to the next one, so a colourway error is caught at station 1 rather than discovered at goods-in three weeks later. A line that doubles up stations, folding and polybagging at the same bench for example, is where most of the variance returns and where pack counts start to drift between cartons.

Two numbers make the SOP measurable: units packed per operator per hour, and pack-out accuracy. In campaigns we support, a simple flat fold on a tote or a pouch runs at a considerably higher rate than a structured backpack that must be stuffed and shaped, and that difference belongs in the packing cost line rather than hidden inside a general labour figure. It also belongs in the plan for crowdfunding rewards fulfilment, where pick time is charged back to you.

Folding method by bag format

A single folding rule applied across every format is the most common packing error on a multi-SKU reward programme. A tote wants a flat fold along its natural crease with the handles laid inside. A structured backpack wants light internal stuffing so the back panel keeps its shape, then a fold that does not press the shoulder straps into a hard crease. A duffle wants a roll that protects the base panel, and a drawstring wants to be flattened and rolled rather than folded twice.

Material behaviour decides whether a fold is reversible. Uncoated cotton canvas relaxes, and a fold line disappears after a day of use. A polyurethane or TPU laminate takes a crease that can crack the coating permanently. Non-woven polypropylene holds a fold line and can crease white at the fold. Specify the fold with the material in mind, and test it on the approved sample unit rather than on a flat fabric swatch, because a swatch will not show how a panel corner behaves.

• Specify the fold in the pack with a photograph of the reference unit, not a written description alone.
• Set a flat thickness tolerance in millimetres so the packer has a clear pass or fail test at the bench.
• Protect hardware: zip pullers, buckles and metal feet should never sit directly against the face fabric.
• Avoid folding coated or laminated fabrics on the same line twice; a crease set into a TPU laminate rarely recovers.
• Where a structured format is involved, budget the stuffing material and the extra seconds it adds per unit.
• Match the fold method to the custom bag category rather than to a house standard.

Polybag specification: film, gauge, closure and venting

The polybag is the cheapest component in the pack and the one most often left to chance. Three variables matter: film type, gauge, and closure. LDPE is soft, quiet and tear resistant. HDPE is crisper and rustles more, with better clarity. Cast PP gives the clearest, stiffest presentation and is the usual choice for a premium retail pack. Gauge is stated in microns, and the difference between 30 micron and 50 micron film is felt immediately once cartons are stacked inside a container.

Venting is not optional. A polybag sealed around a folded bag traps air, and trapped air inside a container crossing an equatorial route becomes a compression and humidity problem by the time it is discharged. Specify vent holes at a stated diameter and spacing, positioned so they do not break the printed warning. Name the closure too: a self-adhesive flap on a stated edge is the most common fulfilment choice, while a resealable closure suits a pouch that is meant to be reused by the backer.

Size the bag to the folded unit plus clearance. A polybag that is too tight tears at the corners in transit and stresses the taped seam; one that is too loose creates a slack fold that abrades print against print. A working allowance is roughly 20-30 mm of extra width and 30-50 mm of extra length over the folded unit, with the closure sitting on the edge that faces away from the printed panel. Where a hangtag or header card is used, the polybag must be sized over it rather than around it.

Suffocation warnings and market compliance for polybags

Any flexible plastic bag large enough to fit over a child's head must carry a suffocation warning in the language of the destination market. This is a compliance requirement rather than a design preference, and it is checked at goods-in by a number of fulfilment warehouses and by retail buyers. The warning text, its minimum font height and its permitted placement differ by market, which is why the requirement has to sit in the packing specification rather than in a single generic artwork file. Confirm it before the polybag order is placed, because film is printed in a minimum run and cannot be corrected cheaply afterwards.

• United States: printed warning in English, with a minimum print height specified by the applicable standard.
• United Kingdom and European Union: warning in the local language, alongside the product safety information required under EU GPSR.
• Multi-market runs: either print a combined multi-language warning block or hold separate polybag stock per destination.
• Keep the polybag specification inside the compliance file so it can be produced on request by a warehouse or a retail buyer.
• Confirm whether the destination requires a recycling symbol or film identification mark printed on the bag itself.

Labelling: unit, carton and pallet levels

Labelling operates at three levels and each level carries different data. The unit label is what the fulfilment warehouse scans to pick the right colourway for each backer. The carton label is what the warehouse scans to find that unit without opening boxes. The pallet label is what the freight forwarder and the receiving dock use to move the shipment. Getting the data hierarchy right at specification stage is what makes a container reconcile in minutes rather than hours.

Carton numbering matters more than it appears. Number cartons sequentially as 1 of 42, 2 of 42 and so on, and carry that numbering into the packing list. A warehouse receiving a shipment with a mismatched count can reconcile in minutes against a numbered list, or in hours against an unnumbered one. Mixing colourways inside a single carton is the other avoidable error: it saves a little packing time and costs a great deal of pick time later, which is where bag manufacturing for campaign creators separates a smooth run from a noisy one.

Carton selection: board grade, flute and size

Carton choice is a compression problem before it is a cost problem. A carton at the bottom of a stack inside a container carries the weight of everything above it for the length of the transit, in humidity, with vibration. Choosing board on price alone produces crushed corners and, in a bad season, entire collapsed stacks. The specification should therefore name three things: the board construction, the flute profile, and a measurable strength value that can be verified on receipt.

• Name a strength value in the spec: either a bursting test figure or an edge crush test figure, never vague wording such as heavy duty.
• Set a gross weight limit per carton; a common working limit for manual handling sits around 15-20 kg.
• Choose carton dimensions from the pack-out maths first, then round to a standard size a forwarder can palletise efficiently.
• Specify the tape width and sealing method; a single strip on the top seam only is a frequent failure point.
• Avoid void space: an under-filled carton collapses. Use void fill or reduce the carton size.
• Confirm the carton print method: flexo, screen or pre-printed liners each carry different minimum quantities.

Void fill is the other half of the compression problem. A carton packed to 90 per cent of its volume will settle in transit, lose stacking strength and arrive with crushed corners. Options range from recycled paper void fill and honeycomb wrap to moulded pulp end caps and corrugated dividers. Dividers earn their cost on multi-unit cartons because they carry load vertically rather than letting units press on each other, which matters most when the units are structured rather than flat.

Packing density and volumetric weight

Freight is billed on whichever is greater, actual weight or volumetric weight, and on a bag programme volumetric almost always wins. Air freight applies a divisor to the product of the three dimensions; ocean freight is quoted per cubic metre. This is why fold method and carton size are freight decisions rather than warehouse decisions, and why they belong in the same conversation as the unit cost and the production window.

The practical test is simple and should be run during sampling, on a real unit, before any carton order is placed. Pack one carton the way the specification says, measure it, weigh it, and multiply by the number of cartons the run will produce. If the total cubic metres exceed what your freight quote assumed, the difference comes straight out of the reward margin. Most creators discover this the expensive way, after the container has already been booked.

Container utilisation is worth calculating before the carton size is fixed. A standard 40 ft high cube container offers roughly 65-68 cubic metres of usable volume, so a 500 pcs run in cartons of 0.12 cubic metres occupies about one cubic metre and is a rounding error; a 5,000 pcs run in the same cartons occupies roughly ten cubic metres and becomes a real line in the freight budget. The carton decision scales with the order, which is why it should be priced at both volumes in the RFQ.

In-line packing checks before the carton closes

Packing is the last point at which a defect can be caught cheaply. Once a carton is sealed and a container is loaded, the only remedy is a replacement shipment, which costs multiples of the original unit. A short in-line check at the packing station catches the failures that actually generate backer tickets: wrong colourway, wrong size, missing insert, unreadable barcode, damaged polybag, and units that have picked up soil or creasing in the finishing area.

• Scan-verify every unit against the packing list before it goes into the polybag.
• Check the first and last unit of every carton for print quality and logo placement.
• Confirm insert and card orientation, particularly where several language variants are in the same run.
• Reject any unit with a soil mark, loose thread or hardware scratch before it is packed.
• Record pack-out by carton number so a later query traces to a specific box rather than the whole shipment.
• Photograph the first sealed carton of each SKU and keep it as the packing reference.

Retail-ready packaging versus fulfilment packaging

A reward bag shipped directly to a backer and the same bag shipped into a retail channel need different packing. Fulfilment packing optimises for protection and scan accuracy: a plain or lightly printed polybag, a unit barcode, a sealed and numbered carton. Retail packing optimises for shelf presentation: a printed or branded bag, a header card or hangtag, fibre content and care labelling, and usually an individual retail barcode that differs from the fulfilment SKU.

Most first campaigns should pack for fulfilment and hold retail packing for the re-order, once channel volumes are known. If you intend to do both from the first run, say so in the RFQ, because the packing line, the labelling and the carton specification differ and the difference is priced separately. The same applies where you are using print or embroidery that needs protection from abrasion inside the carton.

Where packing sits inside the 35-50 day window

Packing is usually the last three to seven days of the bulk window, immediately before the pre-shipment inspection. Because inspection is carried out on packed cartons, a packing delay delays inspection, and an inspection delay delays the balance payment and the cargo release. Packing is therefore on the critical path even though it looks like an end-of-run task, and it is the stage most often underestimated in a campaign update.

1. Days 1-7: material purchase, receipt and shade checking against the approved standard.
2. Days 5-35: cutting, branding application, sewing and assembly across the allocated production lines.
3. Days 25-40: in-line quality control, finishing, thread trimming and final cleaning.
4. Days 35-45: packing, carton marking, weighing and container planning.
5. Days 42-50: pre-shipment inspection at AQL 2.5 to ISO 2859-1 and cargo release.

The packing specification has to be complete before packing starts, not during it. Carton board, carton dimensions, pieces per carton, polybag film and gauge, insert set, label data and carton numbering all need to be agreed at sample approval, because that is the point at which packing materials are ordered alongside bulk materials. A change requested later means either a delay while film or board is reprinted, or an acceptance that the goods will ship in a pack you did not choose.

The packing detail to include in your RFQ

A packing quotation is only as accurate as the information behind it. Send the folded unit dimensions, the target pieces per carton, the carton board and strength requirement, the polybag film and gauge, the insert and label set, the destination market and the trade term, and the packing cost can be quoted together with the unit cost in one round. Send a sketch and a quantity and you will receive three rounds of questions instead. Our custom bags for Kickstarter page sets out the full pack structure, and the low minimum production page explains how the 500 pcs minimum interacts with packing choices.

• Folded unit dimensions in centimetres, with the fold method described or photographed.
• Target pieces per carton and the maximum acceptable carton gross weight.
• Carton board construction and a stated strength value, either burst or edge crush test.
• Polybag film type, gauge in microns, closure type and venting specification.
• Insert and label set, including any market-specific care, origin or fibre content labelling.
• Destination country, so volumetric weight and compliance requirements are quoted correctly.
• Confirmation that packing is included in the unit cost or priced as a separate line.

• Custom bags for Kickstarter campaigns
• Crowdfunding rewards fulfilment
• Kickstarter campaign bag QA and QC
• Custom bag categories
• Bag manufacturing for campaign creators
• Request a quotation

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