Shrink film packaging wraps a folded garment in film, runs it through a shrink tunnel and lets the heat pull the film tight around the product, producing a close-fitting, transparent pack that cannot be resealed once opened. It suits T-shirts, underwear, socks, towels and multi-piece sets: it holds the fold and makes the shelf look tidy. Choose the wrong film or tunnel temperature, though, and the garment comes out with hard creases — most obvious on napped fabrics.
This guide compares the three mainstream shrink films, explains shrinkage rate and direction, thickness choices, sealing and venting, when a poly bag beats shrink film, printing and marking, and a sampling checklist — so the packaging spec can be settled in one conversation.
1. Three Mainstream Films: PE, POF and Cross-Linked PE
| Film | Clarity | Shrink behaviour | Best for | Watch out for |
|---|---|---|---|---|
| PE (polyethylene) | Medium, slightly hazy | Higher shrink temperature, tougher film | Multi-packs, over-wrapping cartons, heavier items | Gloss is moderate and clarity trails POF |
| POF (polyolefin multilayer) | High clarity, good gloss | Low shrink temperature, fast tunnel speed | Underwear, T-shirts, gift sets | Pricier than PE and easy to puncture on sharp corners |
| Cross-linked PE | Clear and strong | Low temperature, high shrinkage, tightest wrap | Irregular sets that need a tight wrap | Highest unit price and the tunnel temperature must be tightly controlled |
| PVC | High clarity | Low, easy-to-control shrink temperature | Older equipment and a few specific markets | Recycling and environmental limits; most European and North American buyers have moved on |
2. Shrinkage Rate and Direction: Why Packs Distort
- MD versus TD: film shrinks in a machine direction and a transverse direction; a large gap between them pulls the finished pack towards the stronger side
- Typical range: garment packing usually sits at 30%–60% depending on film and equipment; too little leaves it loose, too much drags the carefully folded garment out of shape
- Seal orientation: the seal should run across the main shrink direction so the finished edge stays straight; sealing along it produces a wavy edge
- Test first: run a few pieces from a new roll at production temperature and speed, confirm size and appearance, then go to bulk
3. Thickness: What 15μm to 25μm Really Changes
- 15–17μm: light single items such as T-shirts and socks — it wraps closely but punctures on hard hang tags or sharp corners
- 19–21μm: the general-purpose band where most garment multi-packs sit, balancing appearance and breakage
- 25μm and up: heavy items or long-haul transit that needs abrasion resistance; cost rises and clarity drops slightly
- One rule: structure beats thickness. Whether the fold leaves a sharp corner or the tag sticks out matters more to breakage than a few extra microns
4. Sealing and Venting: Settings and Common Faults
- Sealing method: L-sealer, side-seal (pillow) and shrink-bag sleeving — pick by pack shape and output
- Temperature and speed: too low and the film never fully shrinks and wrinkles; too high and it burns through or turns brittle — dial in the stable setting step by step
- Vent holes: a fully closed pack must have vents, or pressure changes in transit will balloon and burst it
- Tunnel hygiene: leftover film scraps inside the tunnel stick to garments — glaring on pale colours — so clean before each shift
5. Shrink Film or Poly Bag: When Not to Shrink
- Choose film: when you want a tight look, tamper evidence that shows on opening, multi-piece sets held together, and a tidy shelf
- Choose bags: wool, cashmere, brushed knits and high-value tailoring — compression leaves hard creases or flattens the fabric
- Cost maths: film usually costs less per kilo than bags, but add machine, labour and energy and small runs get dearer — compare total cost per order
- Opening experience: online shoppers tear the garment along with the film; zip bags or re-openable poly bags are friendlier to your return rate
6. Printing, Marking and Export Notes
- Printing difficulty: artwork distorts as the film shrinks and needs pre-compensation; for simple graphics a pressure-sensitive label is the easier route
- Required marks: material and recycling code, suffocation warning, barcode or size mark; for the EU, packaging rules on reduction and recyclability apply as well
- Hang tag interaction: shrink wrapping bends paper tags, so place them outside the film or switch to a soft cord and thinner board
- Machine trial: run real product before production and confirm seal width, trim allowance and overall appearance, then freeze the settings and film batch
💡 Tip: the usual cost order is structure first, thickness second. Flattening the sharp corner of a fold and moving the tag outside often cut breakage more than a thicker film — without touching the look.
7. Sampling and Acceptance Checklist
- Supply the actual folded size and unit weight as the basis for film and thickness
- Specify film type, thickness and shrinkage range, and whether high clarity and low tunnel temperature are required
- Confirm the seal type, trim allowance and whether vents are needed to avoid ballooning in transit
- After trial wrapping, check tightness, hard creases, seal strength and whether tags bent
- Confirm the marking content (recycling code, warning, barcode) and whether it is printed directly or labelled
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Choosing shrink film or bags for next season's garments? Send the folded size, unit weight and destination market with your packaging requirements — we will come back with an option and a quote, and samples ship in 3–7 days.
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